Answer:
OH⁻ is the Bronsted-Lowry base.
Explanation:
A Bronsted-Lowry base is a substance that accepts protons. In the chemical equation, OH⁻ accepts a proton from H₂PO₄⁻ to become H₂O. H₂PO₄⁻ would be a Bronsted-Lowry acid because it donates a proton to OH⁻ and becomes HPO₄²⁻.
Hope that helps.
To determine the concentration of chloride ion (Cl-) in a 100 mL sample of ground water, a chemist adds a large enough volume of AgNO3 solution to precipitate all Cl- as AgCl. The mass of the resulting precipitate is 93.9 mg. What is the chloride ion concentration in milligrams of chloride per liter of ground water
Answer:
[tex][Cl^-]=232.3\frac{mgCl^-}{L}[/tex]
Explanation:
Hello,
In this case, we can represent the chemical reaction as:
[tex]Cl^-(aq)+AgNO_3(aq)\rightarrow AgCl(s)+NO_3^-(aq)[/tex]
In such a way, since the mass of the obtained silver chloride is 93.9 mg, we can compute the chloride ions in the ground water by using the following stoichiometric procedure whereas the molar mass of chloride ions and silver chloride are 35.45 g/mol and 143.32 g/mol respectively:
[tex]m_{Cl^-}=93.3mgAgCl*\frac{1mmolAgCl}{143.32mgAgCl}*\frac{1mmolCl^-}{1mmolAgCl} *\frac{35.45mgCl^-}{1mmolCl^-} =23.23mgCl^-[/tex]
Finally, for the given volume of water in liters (0.100L), we compute the required concentration:
[tex][Cl^-]=\frac{23.2mgCl^-}{0.100L}\\[/tex]
[tex][Cl^-]=232.3\frac{mgCl^-}{L}[/tex]
Best regards.
The concentration of chloride ions in the groundwater sample is 230 mg/L.
Calculation of chloride ion concentration:Based on the given information,
The mass of the resulting precipitate, that is, AgCl is 93.9 mg or 0.0939 g. The molar mass of AgCl is 143.2 g/mol.Now the number of moles of AgCl precipitate can be calculated as,
n = Given mass/Molar mass
Now putting the values we get,
[tex]n = \frac{0.939 g}{143.32 g/mol} \\n = 6.5 * 10^{-4}[/tex]
Thus, 6.5 × 10⁻⁴ moles of AgCl comprises 6.5 × 10⁻⁴ chloride ions. Therefore, 6.5 × 10⁻⁴ of chloride ions are present in the sample of 100 ml.
Now the molar mass of chloride ion is 35.453 g/mol, the mass of chloride ion will be,
Mass = Mole × Molar mass
Mass = 6.5 × 10⁻⁴ moles × 35.453 g/mol
Mass = 0.0230 g or 23 mg
The volume of the groundwater sample is 100 ml or 0.1000 L.
Now the concentration of the chloride ions in the sample given is,
C = 23 mg/0.1000 L
C = 230 mg/L
Thus, the concentration of chloride ions in the groundwater sample is 230 grams per liter.
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Question 5 options: The cell potential for an electrochemical cell with a Zn, Zn2 half-cell and an Al, Al3 half-cell is _____ V. Enter your answer to the hundredths place and do not leave out a leading zero, if it is needed.
Answer:
The voltage is [tex]E_{cell} = 0.944 \ V[/tex]
Explanation:
Generally the half reaction for Zn, Zn2 half-cell is mathematically represented as
[tex]Zn_{(s)}[/tex] ⇔ [tex]Zn^{2+}_{ (aq)} + 2e^-[/tex] (reference study academy)
and the electric potential for this is a constant value
[tex]E_{zn } = -0.7618 \ V[/tex]
Generally the half reaction for Al, Al3 half-cell is mathematically represented as
[tex]Al^{3+} _{(aq)} + 3e^-[/tex] ⇔ [tex]Al_{(s)}[/tex]
and the electric potential for this is constant value
[tex]E_{Al } = -1.662 \ V[/tex]
Therefore the cell potential for an electrochemical cell is mathematically represented as
[tex]E_{cell} = E_{zn } - E_{Al }[/tex]
substituting values
[tex]E_{cell} = -0.718 - (-1.662)[/tex]
[tex]E_{cell} = 0.944 \ V[/tex]
Write the equilibrium constant expression for the experiment you will be studying this week. 2. If the equilibrium values of Fe3+, SCN- and FeSCN2+ are 9.5 x 10-4 M, 3.6 x 10-4 M and 5.7 x 10-5 M respectively, what is the value of Kc? 3. Write the general form of the dilution equation. 4. A solution is prepared by adding 18 mL of 0.200 M Fe(NO3)3 and 2 mL of 0.0020 M KSCN. Calculate the initial concentrations of Fe3+ and SCNin the solution.
Answer:
Kc = 166.7
[Fe³⁺] = 0.18 M
[SCN⁻] = 2×10⁻⁴ M
Explanation:
In the reaction of Fe³⁺ and SCN⁻, it is formed a complex:
Fe³⁺ + SCN⁻ ⇄ FeSCN²⁺ Kc
Let's make the expression for Kc → [FeSCN²⁺] / [Fe³⁺] . [SCN⁻]
5.7×10⁻⁵ / 9.5×10⁻⁴. 3.6×10⁻⁴ = 166.7
We determine the mmoles, we add from each reactant:
18 ml . 0.2M = 3.6 mmoles of Fe³⁺
2 ml . 0.002M = 4×10⁻³ mmoles of SCN⁻
General form of the dilution equation is:
Concentrated [C] . Concentrated Volume = Diluted [C] . Diluted Volume
Total volume = 20mL
[Fe³⁺]: 3.6 mmoles /20mL = 0.18 M
[SCN⁻]: 4×10⁻³ mmoles /20mL = 2×10⁻⁴ M
The value should be 1.67 x 10^2
The initial concentration should be 0.18 M and 2.0 x 10^(-4) M
Calculation of the value and initial concentration:The value is
= 5.7 x 10^(-5)/(9.5 x 10^(-4) x 3.6 x 10^(-4))
= 167
= 1.67 x 10^2
we know that
Initial moles = volume x concentration
So,
= 18/1000 x 0.200
= 0.0036 mol
Now
Initial moles = volume x concentration
= 2/1000 x 0.0020
= 4.0 x 10^(-6) mol
So,
Total volume should be
= 18 + 2
= 20 mL
= 0.02 L
Now
Initial concentration
= moles /total volume
= 0.0036/0.02
= 0.18 M
Now
Initial concentration
= moles /total volume
= 4.0 x 10^(-6)/0.02
= 2.0 x 10^(-4) M
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If the sugar concentration in a cell is 3% and the concentration in the cell’s environment is 5%, how can the cell obtain more sugar? {Hint: Sugar is polar and does not pass through the cell membrane easily.}
Select one:
a. Sugar can undergo facilitated diffusion through a channel protein, and no energy is required.
b. The cell must use active transport to pump the sugar in. Energy is required.
c. Sugar can diffuse straight through the phospholipid bilayer.
d. The cell CANNOT obtain more sugar. It is doomed.
The cell can obtain more sugar when the sugar undergo facilitated diffusion through a channel protein, and no energy is required.
FACILITATED DIFFUSION:
Facilitated diffusion is the process whereby molecules move across a cell through the help of carrier/channel proteins. Facilitated diffusion is a type of passive transport and hence, does not require energy to occur. This is because movement occurs down a concentration gradient (high to low). According to this question, the sugar concentration in a cell is 3% and the concentration in the cell’s environment is 5%. This means that the sugar can travel down a concentration gradient across the cell membrane. However, because sugar is a polar molecule and does not pass through the cell membrane easily, a carrier proteins is needed to aid its movement. Therefore, the cell can obtain more sugar when the sugar undergo facilitated diffusion through a channel protein, and no energy is required.Learn more at: https://brainly.com/question/18122054?referrer=searchResults
If powdered platinum metal is used to speed up the following reaction: Cl2(g) 3F2(g) --> 2ClF3(g), what would you classify the platinum as
Answer:
Catalyst
Explanation:
For the reaction:
[tex]Cl_2_(_g_)~+~3F_2_(_g_)->2ClF_3_(_g_)[/tex]
We have a main observation: When platinum is added the reaction goes faster. With this in mind, we have to remember the kinetic equilibrium theory. In figure 1, we have an energy diagram. In which we have an specific energy for the reagents and the products. When the reaction takes place, the reaction has to must go through an energy peak. This energy peak is called "activation energy". When platinum is added the activation energy decreases and the reaction can go faster. Therefore, platinum is a "catalyst", a substance with the ability to reduce the activation energy.
I hope it helps!
When alkanes react with chlorine in the presence of ultraviolet light, chlorine atoms substitute for one or more alkane hydrogen atoms. What is the number of different chloroalkane compounds that can be formed by the reaction of C2H6 with chlorine?
Answer:
6
Explanation:
Alkanes undergo substitution reaction so the number of replacement reaction hydrogen is 6
Draw the Lewis structure of N₂O₄ and then choose the appropriate pair of hybridization states for the two central atoms. Your answer choice is independent of the orientation of your drawn structure.
Answer:
See explanation
Explanation:
In this case, we have to keep in mind the valence electrons for each atom:
N => 5 electrons
O => 6 electrons
If the formula is [tex]N_2O_4[/tex], we will have in total:
[tex](5*2)+(6*4)=34~electrons[/tex]
Additionally, we have to remember that each atom must have 8 electrons. So, for oxygens 5 and 3 we will have 3 lone pairs and 1 bond (in total 8 electrons. For oxygens, 6 and 4 we will have 2 lone pairs and 2 bonds (in total 8 electrons) and for nitrogens 1 and 2 we will have 4 bonds (in total 8 electrons).
To find the hybridization, we have to count the atoms and the lone pairs around the nitrogen. We have 3 atoms and zero lone pairs. If we take into account the following rules:
[tex]Sp^3~=~4[/tex]
[tex]Sp^2~=~3[/tex]
[tex]Sp~=~2[/tex]
With this in mind, the hybridization of nitrogen is [tex]Sp^2[/tex].
See figure 1
I hope it helps!
The central nitrogen atoms in N2O4 are both sp2 hybridized.
The Lewis structure shows the number of electron pairs that surround the atoms in a molecule as dots. It is quite easy to determine the number of valence electrons in a molecule simply by observing its Lewis dot structure.
The molecule N2O4 has 34 valence electrons as shown in its dot electron structure. The central nitrogen atoms in N2O4 are both sp2 hybridized as shown. The formal charges on each atom in N2O4 are also shown.
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What is the total number of electrons that can occupy the p sublevel? (3 points)
Select one:
a. 2 electrons
b. 6 electrons
c. 8 electrons
d. 10 electrons
Answer:
The answer is 6 because the p sublevel holds 3 orbitals and since each orbital can hold 2 electrons, the answer is 3 * 2 = 6.
Answer:
6 electrons
Explanation:
Each principal energy level above the first contains one s orbital and three p orbitals. A set of three p orbitals, called the p sublevel, can hold a maximum of six electrons. So the answer is 6 electrons.
· A 0.100g sample of Mg when combined with O2 yields 0.166g of Mgo, a
second Mg sample with a mass of 0.144g is also combined with O2. What
mass of MgO is produced from the second sample?
Answer:
[tex]m_{MgO}=0.239gMgO[/tex]
Explanation:
Hello,
In this case, the chemical reaction between magnesium and oxygen to yield magnesium oxide is:
[tex]2Mg+O_2\rightarrow 2MgO[/tex]
In such a way, for 0.144 g of magnesium reacting with sufficient oxygen, the mass of magnesium oxide, whose molar mass is 40.3 g/mol (2:2 mole ratio) turns out:
[tex]m_{MgO}=0.144gMg*\frac{1molMg}{24.3gMg} *\frac{2molMgO}{2molMg}* \frac{40.3gMgO}{1molMgO} \\\\m_{MgO}=0.239gMgO[/tex]
Best regards.
2,4-Dimethylpent-2-ene undergoes an electrophilic addition reaction in the presence of HBr to form 2-bromo-2,4-dimethylpentane. Complete the mechanism of this addition and draw the intermediates formed as the reaction proceeds.
Draw all missing reactants and/or products in the appropriate boxes by placing atoms on the canvas and connecting them with bonds. Add charges where needed. Electron flow arrows should start on the electron(s) of an atom or a bond and should end on an atom, bond, or location where a new bond should be created.
Answer:
the answer is in the diagram
Explanation:
when 2,4-dimethylpent-2-ene undergo electrophilic addition reaction in the presence of HBr to form 2-bromo-2,4-dimethylpentane, it firstly lead to an intermediate carbocation
A carbocation can be describe as an organic molecule, which serves as an intermediate, that has a carbon atom bearing a positive charge and three bonds instead of four
A major component of gasoline is octane, C8H18. When octane is burned in air, it chemically reacts with oxygen gas (O2) to produce carbon dioxide (CO2) and water (H2O) . What mass of carbon dioxide is produced by the reaction of 3.2g of oxygen gas? Round your answer to 2 significant digits.
Answer:
[tex]m_{CO_2}=2.8gCO_2[/tex]
Explanation:
Hello,
In this case, the combustion of octane is chemically expressed by:
[tex]C_8H_{18}+\frac{25}{2} O_2\rightarrow 8CO_2+9H_2O[/tex]
In such a way, due to the 25/2:8 molar ratio between oxygen and carbon dioxide, we can compute the yielded grams of carbon dioxide (molar mass 44 g/mol) as shown below:
[tex]m_{CO_2}=3.2gO_2*\frac{1molO_2}{32gO_2} *\frac{8molCO_2}{\frac{25}{2}molO_2 } *\frac{44gCO_2}{1molCO_2}\\ \\m_{CO_2}=2.8gCO_2[/tex]
Best regards.
When the owners of some wells in Pallerla started using high-powered motors to
draw water from the wells, the owners of other wells noticed that their wells were
drying up. Discuss the possible solution to the problem solutions to the problem
Answer:
The possible solution is to balance the rate of water removal from the well to the rate of natural recharge of the well from its underground aquifer.
Explanation:
A well is an excavation in the earth, made with the aim of extracting water from the aquifers. The water from a well can be drawn up by the means of a pump, containers, such as buckets, or by hand. Aquifers can also be recharged through a well.
Well draw down occurs when water from the well is drained faster than it is naturally recharged from the aquifer. This can be as a result of over pumping, extended drought, among other factors. The use of the high-powered motor in this case, for pumping, might be the possible cause of the well drying up. The situation might have resulted from the pump drawing out water from the well at a rate tat exceeds the rate at which it is recharged naturally, causing the well water to start drying up. There's also a possibility that the well is pumped indiscriminately, possibly leading to wastage of water.
The solution to this problem is to give the well a time duration for it to recharge itself. Then, the rate of recharges should be calculated and determined by an hydrologist. When all these is done, a pump with a motor power that does not exceed the calculated recharge rate should be used in place of the high-powered motor. Also, water usage should be brought to the minimum level to prevent unnecessary pumping due to excessive, wasteful use of water.
For the following reaction at equilibrium, which gives a change that will shift the position of equilibrium to favor formation of more products? 2NOBr(g) 2NO(g) + Br 2(g), ΔHº rxn = 30 kJ/mol
Answer:
Based on the given reaction, it is evident that the reaction is endothermic as indicated by a positive sign of enthalpy of reaction. Thus, it can be stated that the favoring of the forward reaction will take place by upsurging the temperature of the reaction mixture.
Apart from this, based on Le Chatelier’s principle, any modification in the quantity of any species is performed at equilibrium and the reaction will move in such an orientation so that the effect of the change gets minimized. Therefore, a slight enhancement in the concentration of the reactant will accelerate the reaction in the forward direction and hence more formation of the product takes place.
Which of these are elimination reactions? Check all that apply.
CH3OH + CH3COOH → CH3CO2CH3 + H20
C3H7OH → C3H6 + H20
H9C2Br + NaOH → C2H4 + NaBr + H20
Answer:
C3H7OH → C3H6 + H20
Explanation:
If we look at the reactant and the product we will realize that the reactant is an alcohol while the product is an alkene. The reaction involves acid catalysed elimination of water from an alcohol.
Water is a good leaving group, hence an important synthetic route to alkenes is the acid catalysed elimination of water from alcohols. Hence the conversion represented by C3H7OH → C3H6 + H20 is an elimination reaction in which water is the leaving group.
Answer:
B and C. Just finished my lesson on Edge.
Identify the true statements regarding alpha-1,6 linkages in glycogen.
a. New alpha- 1,6 linkages can only form if the branch has a free reducing end
b. The number of sites for enzyme action on a glycogen molecule is increased through alpha- 1,6 linkages
c. At least four glucose residues separate alpha-1,6 linkages
d. These linkages can only be formed on a chain that is exactly 11 residues long.
e. The reaction that forms alpha-1,6 linkages is catalyzed by a branching enzyme.
Answer:
a. New alpha- 1,6 linkages can only form if the branch has a free reducing end
b. The number of sites for enzyme action on a glycogen molecule is increased through alpha- 1,6 linkages
c. At least four glucose residues separate alpha-1,6 linkages
e. The reaction that forms alpha-1,6 linkages is catalyzed by a branching enzyme.
Explanation:
Glycogen i is the main storage polysaccharide in animals. It a homoplymer of (alpha-1-->4)-linked subunits of glucose molecules, with alpha-1--->6)-linked branches.
The alpha-1,6 branches are formed by the glycogen-branching enzyme which catalyzes the transfer of about 7 glucose residues from the non-reducing end of a glycogen branch having at least 11 residues to the C-6 hydroxyl group of a glucose residue which lies inside the same glycogen chain or another glycogen chain, thereby forming a new branch. This ensures that there are at least four glucose residues separating alpha-1,6 linkages.
The effect of branching is that it makes the glycogen molecule more soluble and also increases the number of non-reducing ends, thereby increasing the number of sites for the action of the enzymes glycogen phosphorylase and glycogen synthase.
Which of the following properties should carbon (C) have based on its position on
the periodic table?
A. Shiny
B. Dense
C. Malleable
D. Poor conductor
Answer:
D- poor conductor
Explanation:
metallic properties decrease as we go on the right of the periodic table. Carbon is a non metal hence it is dull and a poor conductor.
it has a low density and is ductile.
Answer: Poor conductor
Explanation:
Write a balanced equation for the single-replacement oxidation-reduction reaction described, using the smallest possible integer coefficients. The reaction that takes place when chlorine gas combines with aqueous potassium bromide. (Use the lowest possible coefficients. Omit states of matter.)
Answer:
[tex]\rm Cl_2 + 2\; KBr \to Br_2 + 2\; KCl[/tex].
One chlorine molecule reacts with two formula units of (aqueous) potassium bromide to produce one bromine molecule and two formula units of (aqueous) potassium chloride.
Explanation:
Formula for each of the speciesStart by finding the formula for each of the compound.
Both chlorine [tex]\rm Cl[/tex] and bromine [tex]\rm Br[/tex] are group 17 elements (halogens.) Each On the other hand, potassium [tex]\rm K[/tex] is a group 1 element (alkaline metal.) EachTherefore, the ratio between [tex]\rm K[/tex] atoms and [tex]\rm Br[/tex] atoms in potassium bromide is supposed to be one-to-one. That corresponds to the empirical formula [tex]\rm KBr[/tex]. Similarly, the ratio between
The formula for chlorine gas is [tex]\rm Cl_2[/tex], while the formula for bromine gas is [tex]\rm Br_2[/tex].
Balanced equation for the reactionWrite down the equation using these chemical formulas.
[tex]\rm ?\; Cl_2 + ?\; KBr \to ?\;Br_2 + ?\; KCl[/tex].
Start by assuming that the coefficient of compound with the largest number of elements is one. In this particular equation, both [tex]\rm KBr[/tex] and [tex]\rm KCl[/tex] features two elements each.
Assume that the coefficient of [tex]\rm KCl[/tex] is one. Hence:
[tex]\rm ?\; Cl_2 + 1 \; KBr \to ?\;Br_2 + ?\; KCl[/tex].
Note that [tex]\rm KBr[/tex] is the only source of [tex]\rm K[/tex] and [tex]\rm Br[/tex] atoms among the reactants of this reaction.
There would thus be one [tex]\rm K[/tex] atom and one [tex]\rm Br[/tex] atom on the reactant side of the equation.
Because atoms are conserved in a chemical equation, there should be the same number of [tex]\rm K[/tex] and [tex]\rm Br[/tex] atoms on the product side of the equation.
In this reaction, [tex]\rm Br_2[/tex] is the only product with [tex]\rm Br[/tex] atoms.
One [tex]\rm Br[/tex] atom would correspond to [tex]0.5[/tex] units of [tex]\rm Br_2[/tex].
Similarly, in this reaction, [tex]\rm KCl[/tex] is the only product with [tex]\rm K[/tex] atoms.
One [tex]\rm K[/tex] atom would correspond to one formula unit of [tex]\rm KCl[/tex].
Hence:
[tex]\displaystyle \rm ?\; Cl_2 + 1 \; KBr \to \frac{1}{2}\;Br_2 + 1\; KCl[/tex].
Similarly, there should be exactly one [tex]\rm Cl[/tex] atom on either side of this equation. The coefficient of [tex]\rm Cl_2[/tex] should thus be [tex]0.5[/tex]. Hence:
[tex]\displaystyle \rm \frac{1}{2}\; Cl_2 + 1 \; KBr \to \frac{1}{2}\;Br_2 + 1\; KCl[/tex].
That does not meet the requirements, because two of these coefficients are not integers. Multiply all these coefficients by two (the least common multiple- LCM- of these two denominators) to obtain:
[tex]\displaystyle \rm 1\; Cl_2 + 2 \; KBr \to 1\;Br_2 + 2\; KCl[/tex].
Automotive antifreeze is typically a 50:50 mixture (by volume) of water and ethylene glycol. Discuss why this solution is useful for protecting automobile engines from both summer and winter temperature extremes.
Answer:
A 50:50 mixture of ethylene glycol and water is effective both summer and winter extremes in temperature because of high boiling point of 106°C and low freezing point of about -37°C. In summer when the average daily temperature rises to about 22°c, the mixture will be effective in keeping the automobile engine cool. Also in winter, when the average temperature falls below 0°C, the mixture will be effective as an antifreeze as it remains a liquid well below 0°C.
Explanation:
Ethylene glycol or antifreeze is an organic compound which is used in automobile engines as a coolant and also as an anti-freezing agent, however it does not conduct heat effectively as water due to its lower heat capacity. It has a freezing point of -12.9°C and boiling point of 197.3°C.
Water is also used as a coolant in automobile engine but it has a limited range due to its boiling point of 100°C. It is also not a good anti-freezing agent due to it high freezing point of 0.°C
However, when ethylene glycol is mixed with water in a ratio of 50:50, the property of the mixture is enhanced to both serve as a coolant and as an antifreeze. The boiling point is elevated to about 106°C while its freezing point is lowered to about -37°C.
This temperature range is effective for both summer and winter temperatures. In summer when the average daily temperature rises to about 22°c, the mixture will be effective in keeping the the automobile engine cool. Also in winter, when the average temperature falls below 0°C, the mixture will be effective as an antifreeze as it remains a liquid well below 0°C.
Which characteristic of life best describes the process of photosynthesis?
Answer:
Using energy.
Explanation:
Which of the following metals is paramagnetic?
A. Magnesium
B. Sodium
C. Beryllium
D. Calcium
Answer:
sodium
Explanation:
(Na) atom is paramagnetic and sodium is a na atom.
Question 7 options: The cell potential of an electrochemical cell made of an Fe, Fe2 half-cell and a Pb, Pb2 half-cell is _____ V. Enter your answer to the hundredths place and do not leave off the leading zero, if needed.
Answer: Thus the cell potential of an electrochemical cell is +0.28 V
Explanation:
The calculation of cell potential is done by :
[tex]E^0=E^0_{cathode}- E^0_{anode}[/tex]
Where both [tex]E^0[/tex] are standard reduction potentials.
[tex]E^0_{[Fe^{2+}/Fe]}= -0.41V[/tex]
[tex]E^0_{[Pb^{2+}/Pb]}=-0.13V[/tex]
As Reduction takes place easily if the standard reduction potential is higher(positive) and oxidation takes place easily if the standard reduction potential is less(more negative). Thus iron acts as anode and lead acts as cathode.
[tex]E^0=E^0_{[Pb^{2+}/Pb]}- E^0_{[Fe^{2+}/Fe]}[/tex]
[tex]E^0=-0.13- (-0.41V)=0.28V[/tex]
Thus the cell potential of an electrochemical cell is +0.28 V
A chemist adds of a mercury(I) chloride solution to a reaction flask. Calculate the micromoles of mercury(I) chloride the chemist has added to the flask.
Answer:
3.383x10⁻³ micromoles of HgCl
Explanation:
The chemist adds 170mL of a 1.99x10⁻⁵mmol/L Mercury (I) chloride, HgCl.
The solution contains 1.99x10⁻⁵milimoles of HgCl in 1L. That means in 170mL = 0.170L there are:
0.170L × (1.99x10⁻⁵milimoles HgCl / L) = 3.383x10⁻⁶ milimoles of HgCl.
Now, in 1milimole you have 1000 micromoles. That means in 3.383x10⁻⁶ milimoles of HgCl you have:
3.383x10⁻⁶ milimoles of HgCl ₓ (1000micromoles / 1milimole) =
3.383x10⁻³ micromoles of HgClFor each of the following, classify the substance as a strong acid, strong base, weak acid, or weak base (or perhaps not acidic or basic). Then determine the pH of the solution and calculate the concentrations of all aqueous species present in the solution.a. 2.0 × 10 ^–2 M HBrb. 1.0 × 10^–4 M NaOHc. 0.0015 M Ba(OH)2 d. 0.25 M HCN e. 2.0 × 10 ^–10 M KOH f. 0.050 M NH3 g. 0.100 M NH4Cl h. 0.200 M CaF2 i. 0.0500 M Ba(NO3)2 j. 0.100 M Al(NO3)3
Answer:
a. Strong acid, pH = 1.69
b. Strong base, pH = 10
c. Strong base, pH = 11
d. Weak acid, pH = 4.90
e. Strong base, pH ≅ 7 (pH should be higher than 7, but the base is so diluted)
f. Weak base, pH = 10.96
g. Acidic salt, pH = 5.12
h. Basic salt, pH = 8.38
i. Neutral salt, pH = 7
j. Acidic salt, pH < 7
Explanation:
a. HBr → H⁺ + Br⁻
Hydrobromic acid is a strong acid.
pH = - log [H⁺]
- log 0.02 = 1.69
b. NaOH → Na⁺ + OH⁻
Sodium hydroxide is a strong base.
pH = 14 - pOH
pOH = - log [OH⁻]
pH = 14 - (-log 0.0001) = 10
c. Ba(OH)₂ → Ba²⁺ + 2OH⁻
Barium hydroxide is a strong base
[OH⁻] = 2 . 0.0015 = 0.003M
pH = 14 - (-log 0.003) = 11
d. HCN + H₂O ⇄ H₃O⁺ + CN⁻
This is a weak acid, it reacts in water to make an equilibrium between the given protons and cyanide anion.
To calculate the [H₃O⁺] we must apply, the Ka
Ka = [H₃O⁺] . [CN⁻] / [HCN]
6.2×10⁻¹⁰ = x² / 0.25-x
As Ka is really small, we can not consider the x in the divisor, so we avoid the quadratic formula.
[H₃O⁺] = √(6.2×10⁻¹⁰ . 0.25) = 1.24×10⁻⁵
-log 1.24×10⁻⁵ = 4.90 → pH
e. KOH → K⁺ + OH⁻
2×10⁻¹⁰ M → It is a very diluted concentration, so we must consider the OH⁻ which are given, by water.
In this case, we propose the mass and charges balances equations.
Analytic concentration of base = 2×10⁻¹⁰ M = K⁺
[OH⁻] = K⁺ + H⁺ → Charges balance
The solution's hydroxides are given by water and the strong base.
Remember that Kw = H⁺ . OH⁻, so H⁺ = Kw/OH⁻
[OH⁻] = K⁺ + Kw/OH⁻. Let's solve the quadratic equation.
[OH⁻] = 2×10⁻¹⁰ + 1×10⁻¹⁴ /OH⁻
OH⁻² = 2×10⁻¹⁰. OH⁻ + 1×10⁻¹⁴
2×10⁻¹⁰. OH⁻ + 1×10⁻¹⁴ - OH⁻²
We finally arrived at the answer [OH⁻] = 1.001ₓ10⁻⁷
pH = 14 - (- log1.001ₓ10⁻⁷) = 7
The strong base is soo diluted, that water makes the pH be a neutral value.
Be careful, if you determine the [OH⁻] as - log 2×10⁻¹⁰, because you will obtain as pOH 9.69, so the pH would be 4.31. It is not possible, KOH is a strong base and 4.30 is an acid pH.
f. Ammonia is a weak base.
NH₃ + H₂O ⇄ NH₄⁺ + OH⁻
Kb = OH⁻ . NH₄⁺ / NH₃
1.74×10⁻⁵ = x² / 0.05 - x
We can avoid the x from the divisor, so:
[OH⁻] = √(1.74×10⁻⁵ . 0.05) = 9.32×10⁻⁴
pH = 14 - (-log 9.32×10⁻⁴ ) = 10.96
g. NH₄Cl, an acid salt. We dissociate the compound:
NH₄Cl → NH₄⁺ + Cl⁻. We analyse the ions:
Cl⁻ does not make hydrolisis to water. In the opposide, the ammonium can react given OH⁻ to medium, that's why the salt is acid, and pH sould be lower than 7
NH₄⁺ + H₂O ⇄ NH₃ + H₃O⁺ Ka
Ka = NH₃ . H₃O⁺ / NH₄⁺
5.70×10⁻¹⁰ = x² / 0.1 -x
[H₃O⁺] = √ (5.70×10⁻¹⁰ . 0.1) = 7.55×10⁻⁶
pH = - log 7.55×10⁻⁶ = 5.12
As Ka is so small, we avoid the x from the divisor.
h. CaF₂ → Ca²⁺ + 2F⁻
This is a basic salt.
The Ca²⁺ does not react to water. F⁻ can make hydrolisis because, the anion is the strong conjugate base, of a weak acid.
F⁻ + H₂O ⇄ HF + OH⁻ Kb
Kb = x² / 2 . 0.2 - x
Remember that, in the original salt we have an stoichiometry of 1:2, so 1 mol of calcium flouride may have 2 moles of flourides.
As Kb is small, we avoid the x, so:
[OH⁻] = √(1.47×10⁻¹¹ . 2 . 0.2) = 2.42×10⁻⁵
14 - (-log 2.42×10⁻⁵) = pH → 8.38
i . Neutral salt
BaNO₃₂ → Ba²⁺ + 2NO₃⁻
Ba²⁺ comes from a strong base, so it is the conjugate weak acid and it does not react to water. The same situation to the nitrate anion. (The conjugate weak base, from a strong acid, HNO₃)
pH = 7
j. Al(NO₃)₃, this is an acid salt.
Al(NO₃)₃ → Al³⁺ + 3NO₃⁻
The nitrate anion is the conjugate weak base, from a strong acid, HNO₃ so it does not make hydrolisis. The Al³⁺ comes from the Al(OH)₃ which is an amphoterous compound (it can react as an acid or a base) but the cation has an acidic power.
Al·(H₂O)₆³⁺ + H₂O ⇄ Al·(H₂O)₅(OH)²⁺ + H₃O⁺
mechanism of 1-iodobutane reacts with pyridine
Answer:
It is an example of elimination reaction through the E2 mechanism.
Explanation:
The reaction between 1-iodobutane and pyridine is an example of an E2 (bimolecular elimination) elimination reaction.
Pyridine acts predominantly as a base and the given alkyl halide is a primary alkyl halide. Both of these two factors facilitate the E2 mechanism.
Here, both H and Cl are eliminated in a single step to produce 1-butene as the product of the reaction.
The reaction mechanism and the structure of the product are shown below.
The mechanism by which 1-iodobutane reacts with pyridine is by the E2 mechanism.
What is Bimolecular Elimination (E2 Mechanism)?
The E2 mechanism process (Bimolecular Elimination) is a one-step reaction mechanism whereby carbon-hydrogen (C-H) and carbon-halogen (C-X) bonds split to generate a double bond. (C = C πbond).
The following characteristics of the E2 reaction are:
It is a one-step elimination andHas only one transition stage.From the information given:
Pyridine functions primarily as a base, and the alkyl iodide in question is a primary alkyl halide that helps in the E2 mechanism.
In this case, both H and Cl are removed in a single step, yielding 1-butene as the byproduct of the reaction.
Learn more about the Bimolecular Elimination reaction here:
https://brainly.com/question/13607621
Which element would have the most valence electrons and also be able to react with hydrogen?
Answer:
Fluorine, Chlorine, Bromine, or Iodine
Explanation:
These all have an ALMOST full valence shell. And they need one more electron so they'd react with hydrogen
Answer:
its chlorine
Explanation:
just trust me do i look like i would lie too you ;-)
btw i just took the test :-)
Calculate the value of ΔG∘rxnΔGrxn∘ for the following reaction at 296 K. Ka = 2.9 × 10–8 and assume Ka does not change significantly with temperature. $$HClO(aq)+H2O(l) HClO−(aq)+H3O+(aq)
Answer:
[tex]\Delta G_{rxn}=42.7\frac{kJ}{mol}[/tex]
Explanation:
In this case, for the dissociation of hypochlorous acid, we know that the acid dissociation constant (Ka) is 2.9x10⁻⁸, which is related with the Gibbs free energy as shown below:
[tex]\Delta G_{rxn}=-RTln(K)[/tex]
But in this case K is just Ka, therefore, at 296 K, it turns out:
[tex]\Delta G_{rxn}=-8.314\frac{J}{mol*K}*296K*ln(2.9x10^{-8})\\\\\Delta G_{rxn}=42.7\frac{kJ}{mol}[/tex]
Such result, means that the reaction is nonspontaneous at the given temperature, it means it is not favorable (not easily occurring).
Best regards.
Write electron configurations for the following ion: Cd2 Cd2 . Express your answer in order of increasing orbital energy. For example, the electron configuration of LiLi would be entered in complete form as 1s^22s^1 or in condensed form as [He]2s^1.
Answer:
Cd2+ : 1s2 2s2 2p6 3s2 3p6 4s2 3d10 4p6 4d10 or [Kr] 4d¹⁰
Explanation:
Before proceeding to write out the electron configuration of Cd2+, we have to obtain the electron configuration of Cadmium (Cd),
Cadmium has an atomic number of 48, this means that a neutral cadmium atom will have a total of 48 electrons surrounding its nucleus.
The electronic configuration of Cadmium is;
Cd: 1s2 2s2 2p6 3s2 3p6 4s2 3d10 4p6 5s2 4d10
The shorthand notation is given as;
Cd: [Kr] 4d¹⁰5s²
Cd2+ means that it has two less electrons, hence it's electron configuration is given as;
Cd2+ : 1s2 2s2 2p6 3s2 3p6 4s2 3d10 4p6 4d10 or [Kr] 4d¹⁰
Consider the following reaction (X = Cl or Br) which statement s is are correct?
CH3CH2CH3 + X2---------CH3CHCH3--X + CH3CH2CH2--X
i. statistically the 1 halopropane should be the major isomer
ii. the 2 halopropane to 1 halopropane ratio is largest when X = Br
iii. the 2 halopropane to 1 halopropane ratio is largest when X = Cl
A. only Il
B. only Ill
C. I and II
D. I and III
A.S OLOS kkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkll
plez hurry Which is an important safety precaution that should be taken during a tornado? Stay away from doors and windows. Move to high ground to avoid flood waters. Try to avoid the storm by driving or running. Stay outside to avoid being trapped in a building.
Answer: stay away from doors and windows.
Explanation:
to aviod geting hit by glass
Answer:
Stay away from doors and windows.
Explanation:
Always stay in the center of the room during a tornado storm. Avoid windows, doors, and corners. If you’re near a window, the glass can shatter and hurt you.
Predict the order of acid strengths in the following series of cationic
species: CH3CH2NH3
+, CH3CH=NH2
Answer:
CH3CH=NH2+>CH3CH2NH3+
Explanation:
A close examination of both structures will reveal that they are both amines hence they must have the polar N-H bond.
Electrons usually move towards the nitrogen atom and this makes both compounds acidic. We must also remember that some features of a compound may make it more acidic than another of close resemblance. Being more acidic may imply that the proton of the N-H is more easily lost.
CH3CH=NH2+ has an sp2 hybridized carbon atom in its structure which is known to be very electronegative due to increasing s character of the bond. It will withdraw electron density from the N-H bond thereby leading to a greater acidity of CH3CH=NH2+ in comparison to CH3CH2NH3+