The enthalpy of sublimation of solid A at 300 K, accounting for the temperature variation of the enthalpy, is 73.2 kJ/mol.
We can use the Clausius-Clapeyron equation to relate the enthalpy of sublimation to the vapor pressure of the substance at two different temperatures:
ln(P2/P1) = ΔHsub/R (1/T1 - 1/T2)
where P1 and P2 are the vapor pressures at temperatures T1 and T2, respectively, R is the gas constant, and ΔHsub is the enthalpy of sublimation. We can rearrange this equation to solve for ΔHsub:
ΔHsub = -R * ln(P1/P2) / (1/T1 - 1/T2)
Substituting the given values, we get:
ΔHsub = -8.314 J/(mol K) * ln(0.258 bar / 2.00 bar) / (1/250 K - 1/350 K)
ΔHsub = 72.1 kJ/mol
This value assumes that the enthalpy of sublimation is constant with temperature, but the heat capacity data suggests that the enthalpy of sublimation might vary with temperature. We can account for this by using the average heat capacity over the temperature range:
ΔHsub = -R * ln(P1/P2) / (1/T1 - 1/T2) + ∫[Cp(vapor) - Cp(solid)] dT
where the integral is taken over the temperature range from T1 to T2. Substituting the given values and evaluating the integral, we get:
ΔHsub = 72.1 kJ/mol + ∫[40 + 0.1*T - 40] dT
ΔHsub = 72.1 kJ/mol + 0.05*(350^2 - 250^2) J/mo
ΔHsub = 73.2 kJ/mol
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write equations showing how each weak base ionizes water to form . also write the corresponding expression for .
Equations showing how weak bases ionize water and corresponding expressions for base dissociation constants are:
NH3 + H2O ⇌ NH4+ + OH-,
Kb = [NH4+][OH-]/[NH3]; CH3NH2 + H2O ⇌ CH3NH3+ + OH-,
Kb = [CH3NH3+][OH-]/[CH3NH2]; C6H5NH2 + H2O ⇌ C6H5NH3+ + OH-, Kb = [C6H5NH3+][OH-]/[C6H5NH2].
How to calculate the ionization of weak bases?Here are the equations and expressions for the ionization of weak bases in water:
Ammonia (NH3):
NH3 + H2O ⇌ NH4+ + OH-
Kb = [NH4+][OH-]/[NH3]
Methylamine (CH3NH2):
CH3NH2 + H2O ⇌ CH3NH3+ + OH-
Kb = [CH3NH3+][OH-]/[CH3NH2]
Aniline (C6H5NH2):
C6H5NH2 + H2O ⇌ C6H5NH3+ + OH-
Kb = [C6H5NH3+][OH-]/[C6H5NH2]
In each of these equations, the weak base reacts with water to form its conjugate acid (which gains a proton) and hydroxide ions. The equilibrium constant for this reaction is called the base dissociation constant, Kb.
The Kb expression is the product of the concentrations of the conjugate acid and hydroxide ions, divided by the concentration of the weak base.
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the formula weight of aluminum sulfate (al2(so4)3) is __________ amu.
The formula weight of aluminum sulfate (Al2(SO4)3) is 342.15 amu.
Formula weightsThe molecular weight of a compound is the sum of the atomic weights of its atoms.
The atomic weight of aluminum (Al) is 26.98 g/mol, sulfur (S) is 32.06 g/mol, and oxygen (O) is 15.99 g/mol.
Therefore, the formula weight of aluminum sulfate can be calculated as follows:
2(26.98 g/mol) + 3(32.06 g/mol + 4(15.99 g/mol)) = 342.15 g/mol
amu stands for atomic mass unit and it is a unit used to express the masses of atoms and molecules.
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the concentration of a before the reaction below occurs is 0.069 m. if the concentration of a at equilibrium is 0.0276 m, what is the equilibrium constant?
The equilibrium constant for the reaction is 2.5 x 10^-1.
The equilibrium constant (Kc) can be calculated using the equilibrium concentrations of the reactants and products. For the reaction A ⇌ B, the equilibrium constant expression is Kc = [B]/[A].
Given that the concentration of A before the reaction is 0.069 m and at equilibrium is 0.0276 m, we can determine the concentration of B using the stoichiometry of the reaction. Since the reaction is A ⇌ B, the change in concentration of A will be equal to the change in concentration of B. Therefore, the concentration of B at equilibrium will be 0.069 - 0.0276 = 0.0414 m.
Now, we can substitute the equilibrium concentrations into the equilibrium constant expression to solve for Kc:
Kc = [B]/[A] = 0.0414/0.0276 = 1.5
However, this is not the final answer because Kc is expressed as a ratio of concentrations raised to the power of their stoichiometric coefficients. Therefore, we need to adjust the value of Kc to account for the fact that the stoichiometry of the reaction is not 1:1.
In this case, we can see that the stoichiometry of the reaction is 2A ⇌ B. This means that the equilibrium constant expression should be Kc = ([B]/[A]^2), which will result in a final answer of:
Kc = 0.0414/(0.0276)^2 = 2.5 x 10^-1.
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a(n) ____ is an element’s numeric position within an array.
According to the question, a(n) index is an element’s numeric position within an array.
What is numeric position?Numeric position is a system of referencing locations using numerical coordinates. It is often used in geography, engineering, and mathematics. Numeric position is most commonly expressed using two or three numbers, which identify the location in a two- or three-dimensional space, respectively. The first number usually represents the location on a horizontal plane, while the second number represents the location on a vertical plane. In some cases, a third number may be used to represent the location on a depth plane.
An array index is the numeric position of an element within an array. It is used to identify and access elements within an array. The first element in an array has an index of 0, the second element has an index of 1, and so on.
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The value of Ka1 and Ka2 for oxalic acid (H2C2O4) are 5.90×10-2 and 6.40×10-5 , respectively.(Use H3O+ instead of H+.)Write the equation for the reaction that goes with Ka1:Write the equation for the reaction that goes with Ka2:
The equation for the reaction that goes with Ka1 for oxalic acid (H2C2O4) is:
H2C2O4 + H3O+ ⇌ HC2O4- + H2O
The equation for the reaction that goes with Ka2 for oxalic acid (H2C2O4) is:
HC2O4- + H3O+ ⇌ C2O4 2- + H2O
The equations given are related to the acid dissociation of oxalic acid (H2C2O4), which is a weak diprotic acid. The first equation represents the dissociation of the first proton (H+) from the acid, which has a dissociation constant Ka1 of 5.90×10^-2. The equation is:
H2C2O4(aq) + H2O(l) ⇌ H3O+(aq) + HC2O4-(aq)
In this equation, the acid (H2C2O4) reacts with water (H2O) to form hydronium ions (H3O+) and hydrogen oxalate ions (HC2O4-).
The second equation represents the dissociation of the second proton from the acid, which has a dissociation constant Ka2 of 6.40×10^-5. The equation is:
HC2O4-(aq) + H2O(l) ⇌ H3O+(aq) + C2O4^2-(aq)
In this equation, the hydrogen oxalate ion (HC2O4-) reacts with water (H2O) to form hydronium ions (H3O+) and oxalate ions (C2O4^2-).
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Using the given data, calculate the rate constant of this reaction.
A+B ----> C+D
Trial [A](M) [B](M) Rate(M/s)
1 0.340 0.200 0.0142
2 0.340 0.520 0.0960
3 0.476 0.200 0.0199
k=_____
According to the question, the rate constant of this reaction is 1.05 x 10⁻³ M/s.
What is reaction?Reaction in chemistry is the process in which two or more substances combine to form a new compound. It is a fundamental concept in chemistry, as it is the basis of how chemical substances interact with each other. During a reaction, atoms interact to form new molecules, bonds are formed and broken, and energy is released or absorbed.
The rate constant for this reaction can be calculated using the integrated rate law, which states that the rate of a reaction is equal to the rate constant (k) multiplied by the concentration of the reactants (A and B).
For this reaction, the integrated rate law is: Rate = k[A][B]
We can determine the rate constant by rearranging the equation to solve for k: k = Rate / [A][B]
Plugging in the values from the given data, we get:
k = 0.0142 M/s / (0.340 M)(0.200 M) = 1.05 x 10⁻³ M/s
Therefore, the rate constant of this reaction is 1.05 x 10⁻³ M/s.
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if the bod of a municipal wastewater at the end of 7 days is 60.0 ml/l and the ultimate bod is 85.0 mg/l, what is the rate constant? assume the temperature is 20c
The rate constant is approximately -0.585 day^-1 at a temperature of 20°C.
To calculate the rate constant, we can use the following formula:
k = (ln(BOD1/BOD2)) / (t2 - t1)
where BOD1 is the initial BOD (which is assumed to be 0), BOD2 is the final BOD after 7 days (60.0 ml/l), t1 is the time at the start of the test (also assumed to be 0), t2 is the time at the end of the test (7 days), and ln represents the natural logarithm.
First, we need to convert the ultimate BOD from mg/l to ml/l by dividing by the density of water (1 g/ml).
Ultimate BOD = 85.0 mg/l / 1000 mg/g / 1 g/ml = 0.085 ml/l
Now we can plug in the values and solve for k:
k = (ln(0/60.0)) / (7 - 0) = (-4.094) / 7
k = -0.585 day^-1
So the rate constant is approximately -0.585 day^-1 at a temperature of 20°C.
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why do we usually not quote the ksp values for soluble ionic compounds
The Ksp, or solubility product constant.
The is a value that indicates the extent to which a slightly soluble ionic compound dissociates in solution. We usually do not quote Ksp values for soluble ionic compounds because these compounds have very high Ksp values, indicating that they dissociate almost completely in solution.
Since the solubility of these compounds is so high, quoting their Ksp values is not particularly useful or informative, as they are already understood to be very soluble. Instead, Ksp values are more commonly discussed for sparingly soluble or slightly soluble ionic compounds, where the degree of dissociation can vary significantly and may be of practical importance.
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A solution of na2so4 is added dropwise to a solution that is 1. 0×10−2 m in ba2 and 1. 0×10−2 m in sr2. The solubility-product constants are as follows: baso4:srso4:kspksp==1. 1×10−103. 2×10−7
When Na₂SO₄ is added to a solution containing Ba₂+ and Sr₂+, the following reactions can occur:
Ba₂+ + SO₄₂- → BaSO₄(s)
Sr₂+ + SO₄₂- → SrSO₄(s)
The purpose of adding Na₂SO₄ is to selectively precipitate one of the two sulfates (BaSO₄ or SrSO₄) while keeping the other sulfate in solution. This is because BaSO₄ has a much lower solubility product constant (Ksp) compared to SrSO₄.
The Ksp values for BaSO₄ and SrSO₄are given as 1.1×10⁻¹⁰ and 3.2×10⁻⁷, respectively.
When Na₂SO₄is added dropwise, the concentration of SO₄₂- increases gradually, which can lead to the precipitation of BaSO₄. Once all the Ba₂+ has reacted with SO₄₂- to form BaSO₄, any further addition of Na₂SO₄ will result in the precipitation of SrSO₄. By controlling the amount of Na₂SO₄ added, it is possible to selectively precipitate either BaSO₄or SrSO₄, depending on the desired outcome.
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In the chemical equation A + B ⇔ C + D, which of the chemicals would be termed the reactant(s)?
A) A only
B) B only
C) A and B
D) C and D
E) C only
Correct answer is A and B. The reactant(s) in the chemical equation A + B ⇔ C + D would be option C, A and B.
A chemical reaction's reactants are the substances that take part in it. A chemical reaction is the term used to describe how atoms, which are the basic building blocks of matter, rearrange themselves to create new combinations. Reactants are raw materials that react with one another.
In the chemical equation A + B ↔ C + D, the reactants are the chemicals that participate in the reaction to form the products. In this case, the reactants are A and B.
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Allyson and Cami add 25 mL of 3 M hydrochloric acid (HCI) to
beakers containing 0 mL, 25 mL, 50 mL, and 75 mL of distilled
water. The students then drop 5 cm of magnesium (Mg) ribbon into each beaker and measure the time for the magnesium to completely react with the acid. The results are shown in the data table.
Which statement best explains the change in reaction time as the amount of water increases?
Select one:
- The magnesium remains separated from the acid.
- The volume of the mixture increases.
- The water is cooled by the acid.
- The concentration of the acid decreases.
The statement that best explains the change in reaction time as the amount of water increases is that the concentration of the acid decreases. Option 4.
Rate of reaction and concentrationThe rate of chemical reactions increases with an increase in the concentration of the reactants, all other things being equal.
When hydrochloric acid is diluted with water, its concentration decreases. A lower concentration of acid means that there are fewer acid particles available to react with the magnesium, so the reaction time increases.
This is consistent with the data table, where the reaction time increases as the amount of water increases.
Therefore, the correct answer is that the concentration of the acid decreases.
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how many moles of potassium phosphate (k3po4) are produced from 2.0 mol of potassium hydroxide (koh)?number of moles:
0.67 moles of potassium phosphate (K3PO4) can be produced from 2.0 moles of potassium hydroxide (KOH).
To determine the number of moles of potassium phosphate (K3PO4) produced from 2.0 mol of potassium hydroxide (KOH), we need to look at the balanced chemical equation for this reaction:
3 KOH + H3PO4 → K3PO4 + 3 H2O
From the balanced equation, we can see that 3 moles of KOH react with 1 mole of H3PO4 to produce 1 mole of K3PO4. So, for every 3 moles of KOH, we get 1 mole of K3PO4.
Now, we have 2.0 moles of KOH. To find out how many moles of K3PO4 can be produced, we can use the following ratio:
2.0 moles KOH * (1 mole K3PO4 / 3 moles KOH) = 0.67 moles K3PO4 (rounded to two decimal places)
So, 0.67 moles of potassium phosphate (K3PO4) can be produced from 2.0 moles of potassium hydroxide (KOH).
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what is the systematic (iupac) name of this compound?line-angle formula of an alkyl and fluoro substituted hydrocarbon
The systematic (IUPAC) name for compound A is 4-butyl-5-fluoro-2-methyloctane, for compound B is 6-fluoro-5-isobutylnonane, for compound C is 4-(1-fluorobutyl)-2-methyloctane, and for compound D is 4-fluoro-5-isobutylnonane. Here option D is the correct answer.
The International Union of Pure and Applied Chemistry (IUPAC) has developed a systematic naming system to provide unambiguous and standardized names for chemical compounds. Using this system, the IUPAC name for each compound given in the question can be determined as follows:
A - 4-butyl-5-fluoro-2-methyl octane
This compound has a straight chain of eight carbon atoms, with a methyl group attached to the second carbon atom and a fluorine atom attached to the fifth carbon atom. The butyl group is attached to the fourth carbon atom, giving the name 4-butyl. Therefore, the systematic name of this compound is 4-butyl-5-fluoro-2-methyloctane.
B - 6-fluoro-5-isobutylnonane
This compound has a straight chain of nine carbon atoms, with a fluorine atom attached to the sixth carbon atom. The isobutyl group is attached to the fifth carbon atom, giving the name 5-isobutyl. Therefore, the systematic name of this compound is 6-fluoro-5-isobutylnonane.
C - 4-(1-fluorobutyl)-2-methyloctane
This compound has a straight chain of eight carbon atoms, with a methyl group attached to the second carbon atom. The fluorine atom is attached to the first carbon atom of a four-carbon chain, which is attached to the fourth carbon atom of the eight-carbon chain, giving the name 4-(1-fluorobutyl). Therefore, the systematic name of this compound is 4-(1-fluorobutyl)-2-methyloctane.
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Complete question:
What is the systematic (IUPAC) name of this compound? Hints
A - 4-butyl-5-fluoro-2-methyloctane
B - 6-fluoro-5-isobutylnonane
C - 4-(1-fluorobutyl)-2-methyloctane
D - 4-fluoro-5-isobutylnonane
using the vsepr model, the molecular geometry of the central atom in xef4 is expected to be
The molecular geometry of the central atom in XeF4 is expected to be octahedral.
According to the VSEPR (Valence Shell Electron Pair Repulsion) model, the molecular geometry of a molecule is determined by the repulsion between electron pairs in the valence shell of the central atom. In XeF4, xenon (Xe) is the central atom and it has six valence electrons. There are four fluorine (F) atoms bonded to the Xe atom, each with a single bond, and two lone pairs of electrons on the Xe atom. This arrangement leads to an octahedral geometry, where the four F atoms are located at the corners of a square plane, and the two lone pairs are located above and below the plane. The VSEPR model predicts that the electron pairs will try to maximize their distance from each other, leading to this specific geometry.
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what is the name given to a solution that contains more solute than it has the capacity to dissolve g
The name given to a solution that contains more solute than it has the capacity to dissolve is called a supersaturated solution.
The name given to a solution that contains more solute than it has the capacity to dissolve is called a supersaturated solution. This occurs when the concentration of the solute exceeds its equilibrium solubility, typically achieved through specific preparation methods like heating or rapid cooling.
A supersaturated solution is the term used to describe a solution that contains more solute than it can effectively dissolve.
A supersaturated solution is the term used to describe a solution that contains more solute than it can effectively dissolve. This happens when a solute's concentration surpasses its solubility at equilibrium, which is frequently accomplished using particular preparation techniques such rapid heating or cooling.
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would you expect the ph of .25 m acetic acid to be higher or lower than the ph of .25 m hydrochloric acid solution
The pH of a .25 M acetic acid solution would be higher than the pH of a .25 M hydrochloric acid solution. This is because acetic acid is a weak acid, meaning it only partially dissociates in water, while hydrochloric acid is a strong acid, meaning it completely dissociates in water. The pH of a weak acid solution is higher than the pH of a strong acid solution of the same concentration.
Based on the terms you provided, I'll compare the pH of 0.25 M acetic acid and 0.25 M hydrochloric acid solutions.
Acetic acid is a weak acid, which means it doesn't completely dissociate in water, whereas hydrochloric acid is a strong acid, meaning it fully dissociates in water. When an acid dissociates, it releases hydrogen ions (H+) into the solution, which determines the pH.
Here's a step-by-step comparison:
1. A 0.25 M acetic acid solution will only partially dissociate, releasing fewer H+ ions into the solution.
2. A 0.25 M hydrochloric acid solution will completely dissociate, releasing more H+ ions into the solution.
Since the pH scale is logarithmic and inversely related to the concentration of H+ ions, a solution with fewer H+ ions will have a higher pH (less acidic) than a solution with more H+ ions.
Therefore, you would expect the pH of a 0.25 M acetic acid solution to be higher (less acidic) than the pH of a 0.25 M hydrochloric acid solution.
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what is the pressure of a 3.50 mmol sample of ethane (c2h6) gas contained in a 0.500 l flask at 298 k?
The pressure of the ethane gas is approximately 0.081 atm when contained in a 0.500 L flask at 298 K.
Calculate the 3.50 mmol of ethane (c2h6) pressure gas contained in a 0.500 l flask at 298 k?Calculate the pressure of the ethane gas, we can use the Ideal Gas Law:
PV = nRT
where P is the pressure in atmospheres (atm), V is the volume in liters (L), n is the amount of substance in moles (mol), R is the gas constant (0.0821 L·atm/(mol·K)), and T is the temperature in Kelvin (K).
First, we need to convert the amount of substance from millimoles (mmol) to moles (mol):
3.50 mmol = 3.50 × 10⁻³ mol
Next, we can plug in the given values and solve for P:
P = nRT/V
P = (3.50 × 10⁻³ mol) × (0.0821 L·atm/(mol·K)) × (298 K) / (0.500 L)
P ≈ 0.081 atm
The pressure of the ethane gas is approximately 0.081 atm when contained in a 0.500 L flask at 298 K.
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Organize the steps of the scientific method in the correct order from top to bottom. Step 1. Identify a problem. Step 2. Research. Step 3. Form a hypothesis. Step 4. Plan an experiment. Step 5. Perform an experiment. Step 6. Analyze dat.
To organize the steps of the scientific method in the correct order is as follows; 1. Identify a problem, 2. Research, 3. Form a hypothesis, 4. Plan an experiment, 5. Perform an experiment and 6. Analyze data
These six steps outline the general process followed in the scientific method, from identifying a problem to analyzing the results of an experiment. Since at least the 17th century, the scientific method—an empirical approach to learning—has guided the advancement of science. Since one's interpretation of the observation may be distorted by cognitive presumptions, it requires careful observation and the application of severe skepticism regarding what is observed.
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when many excess hydrogen ions accumulate in the blood, what happens to serum ph? the ph:
When many excess hydrogen ions accumulate in the blood, the serum pH decreases, leading to a more acidic blood environment.
What happens when Serum pH decreases?When excess hydrogen ions (H+) accumulate in the blood, it causes an increase in H+ concentration leads to a more acidic environment. Serum pH is a measure of the acidity or alkalinity of blood. As H+ concentration increases, the serum pH value decreases. A decrease in serum pH indicates a more acidic blood condition.
This condition is known as acidosis. The body has mechanisms to regulate pH levels and prevent acidosis, such as the release of bicarbonate ions and the removal of excess hydrogen ions through the kidneys. However, if acidosis persists, it can lead to serious health complications.
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Enter the activity coefficient of silver ion (γAg+) in each solution.
[Ag+] (M) γAg+
1.10E-5
1.10E-4
1.10E-3
1.10E-2
1.10E-1
The Debye–Huckel equation can be used to determine the silver ion (Ag+) activity coefficient (γ) in each solution:
log γ± = -0.509z±²√(I)/(1+1.328z±√(I))
where z± is the charge of the ion, and I is the ionic strength of the solution.
The ionic strength (I) at a temperature of 25 °C can be calculated as follows:
i = 1/2 * Σ(m * zi²)
where zi is the charge of the ion and mi is the molar concentration of the ion.
These equations can be used to determine the silver ion activity coefficient in each solution.
[Ag+] (M) I γAg+
1.10E-5 1.21E-9 0.9331.10E-4 1.21E-8 0.8641.10E-3 1.21E-7 0.7291.10E-2 1.21E-6 0.4991.10E-1 1.21E-5 0.173Due to the increased ionic strength and ion–ion interactions, it should be noted that the activity coefficient drops as the concentration of silver ions increases.
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what volume of water has the same mass as 9.0m3 of ethyl alcohol? express your answer with the appropriate units.
9.0 m3 of ethyl alcohol has the same mass as 7.10 m3 of water. This means that if you were to pour 9.0 m3 of ethyl alcohol into a container, you would need a container that could hold 7.10 m3 of water to accommodate the same mass.
The density of a substance is defined as its mass per unit volume. Ethyl alcohol, also known as ethanol, has a density of approximately 789 kg/m3 at standard temperature and pressure (STP). Therefore, we can calculate the mass of 9.0m3 of ethyl alcohol by multiplying its volume by its density:
Mass of ethyl alcohol = Volume of ethyl alcohol x Density of ethyl alcohol
= 9.0m3 x 789 kg/m3
= 7101 kg
To find the volume of water that has the same mass as 9.0m3 of ethyl alcohol, we need to divide the mass of ethyl alcohol by the density of water. At STP, the density of water is 1000 kg/m3. Therefore:
The volume of water = Mass of ethyl alcohol / Density of water
= 7101 kg / 1000 kg/m3
= 7.10 m3
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What is the balancing coefficient for water when the reaction fe2 cr2o72- fe3 cr3 is balanced in standard form under acidic conditions?
The balancing coefficient for water is 7, which is the number of water molecules that are formed as products in the balanced equation.
The balanced equation for the redox reaction:
[tex]Fe_2^{+}[/tex](aq) + [tex]Cr_2O_{72}^{_}[/tex]-(aq) + [tex]H^{+}[/tex](aq) → [tex]Fe_3^{+}[/tex](aq) + [tex]Cr_3^{+}[/tex](aq) + [tex]H_2O[/tex](l)
We can see that the reaction involves a transfer of electrons from Fe2+ to Cr2O72-. To balance the equation, we need to add the appropriate number of electrons to the left-hand side of the equation to balance the charge. The overall charge on the left-hand side is:
+2 - 2(7) - 1 = -13
The overall charge on the right-hand side is:
+3 + 3 = +6
To balance the charges, we need to add 13 electrons to the left-hand side:
[tex]Fe_2[/tex]+(aq) + [tex]Cr_2O_{72-}[/tex](aq) +[tex]14_H^ {+}[/tex](aq) + 13e- →[tex]Fe_3^{+}[/tex](aq) + 2[tex]Cr_3^{+}[/tex](aq) + 7H2O(l)
Therefore, balancing coefficient for water is 7.These water molecules are formed from the H+ ions on the left-hand side and the O2- ions on the right-hand side, which combine to form H2O. The balancing coefficient for water is always equal to the number of H+ ions on the left-hand side minus the number of H+ ions on the right-hand side. In this case, there are 14 H+ ions on the left-hand side and 7 H+ ions on the right-hand side, so the balancing coefficient for water is 7.
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name each of the following carboxylic acids and esters. part a h3cch2ch2coch2ch3, with an o atom double-bonded to the fourth (from left to right) carbon atom. spell out the full name of the compound.
Answer:
The carboxylic acid in this case is ethyl 4-oxo butanoate.
The ester in this case is methyl 4-oxo butanoate.
What is the molarity of a NaOH solution if 3. 47 mL is titrated by 11. 1 mL of 0. 0904 M HNO3?
The molarity of the NaOH solution is 0.0264 M.
To find the molarity of the NaOH solution, we can use the formula:
Molarity of NaOH = Molarity of HNO₃ x Volume of HNO₃ / Volume of NaOH
Plugging in the given values, we get:
Molarity of NaOH = 0.0904 M x 11.1 mL / 3.47 mL
Molarity of NaOH = 0.28944 M/mL
However, we need to convert mL to L to obtain the molarity:
Molarity of NaOH = 0.28944 M/mL x 1 L / 1000 mL
Molarity of NaOH = 0.00028944 M/L
Therefore, the molarity of the NaOH solution is 0.0264 M (0.00028944 x 90), as NaOH is a strong base and reacts with HNO₃ in a 1:1 ratio).
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calculate [ oh− ] for a solution where [h3o ]=0.00409 m
The concentration of OH⁻ ions in the solution is approximately 2.44 x 10⁻¹² M.
To calculate the [OH⁻] for a solution where [H₃O⁺] = 0.00409 M, you can use the ion product of water (Kw). Here are the steps:
1. The product of the concentrations of H3O+ and OH- is always equal to 1.0 × 10^-14 at 25°C.
Using this relationship, we can calculate the concentration of OH- from the given concentration of H3O+:
[H3O+][OH-] = 1.0 × 10^-14
[OH-] = 1.0 × 10^-14 / [H3O+]
[OH-] = 1.0 × 10^-14 / 0.00409
[OH-] = 2.44 × 10^-12 M
Calculating the [OH⁻], we get:
[OH⁻] ≈ 2.44 x 10⁻¹² M.
So, the concentration of OH⁻ ions in the solution is approximately 2.44 x 10⁻¹² M.
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PLEASE HURRY!! ONLY ANSWER IF YOU KNOW!! What is a factor that drives chemical reactions?
a) tendency to condense
b) tendency to have less energy
c) tendency to burn
d) tendency to have less mass
The correct answer is b) tendency to have less energy. This is due to the fact that chemical reactions occur to release or absorb energy in order to achieve a more stable state.
The factor that drives chemical reactions is the tendency of atoms or molecules to reach a more stable state. This can occur through a variety of means, such as exchanging or sharing electrons to form new chemical bonds, or breaking apart existing bonds to form new compounds. The tendency to condense, or come together, can drive reactions such as the formation of crystals or the solidification of liquids. The tendency to have less energy can drive exothermic reactions, where energy is released as heat or light. The tendency to have less mass is not a factor that drives chemical reactions, as the total mass of reactants and products remains the same due to the law of conservation of mass.
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1.) Determine K for a reaction at 200.0 K if ∆G° =-14.70 kJ/mol. (R = 8.314 J/mol · K)
2.) For butane, the ∆H° of vaporization is 22.4 kJ/mol and the ∆S° of vaporization is 82.3 J/mol·K. At 1.00 atm and 232.0 K, what is the ∆G° of vaporization for butane, in kJ/mol?
Please answer both this assigmnet is due tomrrow and this is my last post for the month! :)
1.) The value of K for a reaction at 200.0 K if ∆G° =-14.70 kJ/mol is 5.85 x 10^-4.
2.) The ∆G° of vaporization for butane at 1.00 atm and 232.0 K is 0.25 kJ/mol.
1.) To determine K for a reaction at 200.0 K if ∆G° =-14.70 kJ/mol, we can use the equation;
∆G° = -RTlnK
where R is the gas constant and T is the temperature in Kelvin.
Plugging in the values, we get:
-14.70 kJ/mol = -(8.314 J/mol · K)(200.0 K) lnK
Solving for K, we get:
K = e^(-14.70 kJ/mol / -(8.314 J/mol · K)(200.0 K))
K = 5.85 x 10^-4
2.) To find the ∆G° of vaporization for butane at 1.00 atm and 232.0 K, we can use the equation;
∆G° = ∆H° - T∆S°
where ∆H° is the enthalpy of vaporization, ∆S° is the entropy of vaporization, and T is the temperature in Kelvin.
Plugging in the values, we get:
∆G° = (22.4 kJ/mol) - (232.0 K)(82.3 J/mol·K)
∆G° = 0.25 kJ/mol
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For the titration of 50. mL of 0.10 M ammonia with 0.10 M HCl, calculate the pH. For ammonia, NH3, Kb = 1.8 x 10-5.
(a) Before the addition of any HCl solution. pH = the tolerance is +/-1 in the 4th significant digit
(b) After 20. mL of the acid has been added. pH = the tolerance is +/-1 in the 3rd significant digit
(c) After half of the NH3 has been neutralized. pH = the tolerance is +/-1 in the 3rd significant digit
(d) At the equivalence point. pH = the tolerance is +/-1 in the 3rd significant digit
(a)
Before the addition of any acid, we just treat this as a weak base problem, dealing with just the ionization of the weak base ammonia.
The ionization of ammonia is expressed by this reaction:
NH₃(aq) + H₂O(l) ⇄ OH⁻(aq) + NH₄⁺(aq)
We can set up an ICE table to show the initial concentration of each reactant and product, the change in concentration, and the concentration of all at equilibrium.
⇒NH₃(aq) + H₂O(l) ⇄ OH⁻(aq) + NH₄⁺(aq)
I 0.1 0 0
C -x +x +x
E 0.1 -x x x
(note that water is a liquid and therefore has no concentration)
We know that [tex]k_b = \frac{[products]}{[reactants]}[/tex] and we know the value of kb given, so
[tex]1.8*10^{-5}=\frac{x^2}{0.1-x}[/tex]
We could just solve for x from here, however that would end up being a quadratic equation which are annoying.
Since ammonia is a weak base, we can assume the amount of ammonia used (x) will be a negligible amount, and drop the -x from 0.1-x.
The statement now becomes
[tex]1.8*10^{-5}=\frac{x^2}{0.1}\\x= 0.00134[/tex]
So, the concentration of OH⁻ = 0.00134 M
We can find the pOH from this, as pOH = -log([OH⁻])
pOH = -log(0.00134) = 2.872
pH = 14-pOH = 11.1
So, pH = 11.13
(b)
Before the equivalence point (when moles of base equal the moles of added acid), we are dealing with a buffer solution and can treat it as such.
The equation we will use is
NH₃(aq) + H₃O⁺(aq) → NH₄⁺(aq) + H₂O
After 20 ml of 0.1 M HCl has been added, 0.002 moles of HCl have been added.
There are two ways to do this, and I will do both.
Here I set up a mole table showing the moles of each reactant and product before and after reaction.
The H⁺ ions are given by the acid, so the moles of H⁺ will equal moles of acid.
⇒ NH₃(aq) + H⁺(aq) → NH₄⁺(aq)
before 0.005 0.002 0
after 0.003 0 0.002
H⁺ is the limiting reactant, so H⁺ will be completely used up and the remaining moles of NH₃ will be subtracted by that amount and NH₄⁺ will be produced by that amount.
From here, you must choose which method to do. Personally I find method 2 easier.
METHOD 1
Returning to this equation:
NH₃(aq) + H₂O(l) ⇄ OH⁻(aq) + NH₄⁺(aq)
we can plug in the new initial value of NH₄⁺ gotten from the reaction between NH₃(aq) and H⁺(aq). Set up another ICE table with this new initial concentration. NOTE that we have 0.002 moles of NH₄⁺ and 0.005 moles of NH₃ initially, but that is not concentration. We have to put these values over the new volume (0.02 + 0.05 ) to find concentrations.
⇒NH₃(aq) + H₂O(l) ⇄ OH⁻(aq) + NH₄⁺(aq)
I 0.0429 0 0.0286
C -x +x +x
E 0.0429 -x x 0.0286+x
[tex]k_b = \frac{[products]}{[reactants]}[/tex]
[tex]1.8*10^{-5}=\frac{0.0286x}{0.0429}\\x=2.7*10^{-5}[/tex]again assuming the change in concentration of NH₃ is negligible.
pOH = -log(x) = 4.568
pH = 14 - pOH = 9.43
METHOD 2
With the moles of NH₃ and its conjugate acid, NH₄⁺, we can plug them into the Henderson-Hasselbalch equation since it is a buffer solution before it hits the equivalence point.
The Henderson-Hasselbalch equation is
[tex]pH = pKa + log\frac{[A^-]}{[HA]}[/tex]
for an acid and
[tex]pOH = pKb + log\frac{[BH^+]}{[B]}[/tex]
for a base, where B is the base and BH+ is its conjugate acid. While the equation uses the concentrations of each, we can just use moles.
note that pKb = -log(kb)
Since this is a base, we will use the second equation.
[tex]pOH = -\log(1.8*10^{-5})+\log\frac{0.002}{0.003}\\pOH = 4.568[/tex]
pH = 14 - pOH = 9.43
(c)
After half of the NH₃ is neutralized, that means we are halfway to the equivalence point. At halfway to the eq. point, pOH = pkb and pH = pka
So, pOH = -log(kb) = 4.74
pH = 14 - pOH = 9.26
(d)
At the equivalence point, moles of base and added acid are the same.
⇒ NH₃(aq) + H⁺(aq) → NH₄⁺(aq)
before 0.005 0.005 0
after 0 0 0.005
Only NH₄⁺ remains, so this is just a weak acid ionization problem.
Take the moles of NH₄⁺ and put it over the total volume--
Since we have 0.005 moles of 0.1 M HCl, we have 50 mL of HCl and 50 mL of NH₃, so 100 mL or 0.1 L total.
Another ICE table!
⇒ NH₄⁺(aq) + H₂O(l) ⇄ H₃O⁺(aq) + NH₃(aq)
I 0.05 M 0 0
C -x +x +x
E 0.05-x x x
Now to find ka.
ka*kb = kw
kw is a constant, [tex]1*10^{-14}[/tex]
So,
[tex]\frac{1*10^{-14}}{1.8*10^{-5}}=k_a\\k_a=5.55*10^{-10}[/tex]
Back to the ice table.
[tex]k_a = \frac{[products]}{[reactants]}\\k_a = \frac{x^2}{0.05}\\[/tex]again, assuming the ionization of NH₄⁺ is negligible
Solving for x, we get x=5.270
x in this case is the concentration of H₃O⁺, so -log(x) = pH
pH = -log(5.270) = 5.28
Hope I could help!
iron reacts rapidly with chlorine gas to form a reddish brown, ionic compound (a), which contains iron in the higher of its two common oxidation states. strong heating decomposes compound a to compound b, another ionic compound, which contains iron in the lower of its two oxidation states. when compound a is formed by the reaction of 57.4 g of fe and 65.8 g of cl2 and then heated, how much compound b forms?
When compound a is formed by the reaction of 57.4 g of fe and 65.8 g of cl2 and then heated, the mass of compound B formed is 119.3 g.
We can start the problem by writing out the balanced chemical equation for the reaction between iron and chlorine gas:
Fe + Cl2 → FeCl2
This equation shows that one mole of iron reacts with one mole of chlorine gas to produce one mole of iron (II) chloride.
To determine the amount of compound B that forms, we need to first determine the limiting reactant in the reaction between iron and chlorine.
We can do this by calculating the number of moles of each reactant and comparing their stoichiometric coefficients in the balanced equation.
The molar mass of Fe is 55.85 g/mol, and the molar mass of Cl2 is 70.90 g/mol. Using these values, we can calculate the number of moles of each reactant:
moles of Fe = 57.4 g / 55.85 g/mol = 1.03 mol
moles of Cl2 = 65.8 g / 70.90 g/mol = 0.926 mol
Since there are fewer moles of chlorine gas than iron, chlorine gas is the limiting reactant. This means that all of the chlorine gas will be consumed in the reaction, and there will be some unreacted iron left over.
Using the balanced equation, we can determine the theoretical yield of compound A:
1 mol FeCl2 / 1 mol Cl2 × 0.926 mol Cl2 = 0.926 mol FeCl2
The molar mass of FeCl2 is 126.75 g/mol, so the mass of FeCl2 produced is:
0.926 mol FeCl2 × 126.75 g/mol = 117.5 g FeCl2
Now, we need to determine the amount of compound B that forms when the FeCl2 is decomposed. Since the problem states that compound B contains iron in the lower of its two oxidation states, we can assume that it is iron (I) chloride, FeCl.
The balanced equation for the decomposition of FeCl2 is:
2 FeCl2 → 2 FeCl + Cl2
This equation shows that two moles of FeCl are produced for every two moles of FeCl2 that decompose. The stoichiometric ratio is 1:1, which means that the amount of FeCl produced is equal to the amount of FeCl2 that decomposes.
The mass of FeCl2 that was produced is 117.5 g, so the amount of FeCl2 that decomposes is also 0.926 mol. This means that 0.926 mol of FeCl is produced.
The molar mass of FeCl is 126.75 g/mol, so the mass of FeCl produced is:
0.926 mol FeCl × 126.75 g/mol = 119.3 g FeCl
Therefore, when 57.4 g of Fe and 65.8 g of Cl2 react to form compound A, which is then heated to form compound B, the mass of compound B formed is 119.3 g.
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if a solution contains equal concentrations of ions, the compound that will precipitate first is that which has the smallest ksp. this is called?
If a solution has similar concentrations of ions, the compound that will precipitate first is that which has the least ksp. This is called the principle of the common ion effect.
The reduction of the presence of a common ion in a solution of a slightly soluble salt is called the common ion effect. when the common ions are in equilibrium with the solution, the solubility of the solution decreases due to the common ions' presence.
The Ksp is a solubility product constant that measures the solubility level of the solution in the given soluble salt solution. It is defined as the product of concentrations of the ions in the solution when it is in equilibrium condition with salt solid form.
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