The number 38.7 x 10⁷ is already in scientific notation
The coefficient is 38.7 and the exponent is 7.
In the given number, 38.7 x 10⁷, the coefficient is 38.7, which is a decimal number between 1 and 10.
The exponent of 10 is 7, which tells us to move the decimal point seven places to the right to get the actual value of the number.
So, 38.7 x 10⁷ can be expanded as follows:
38.7 x 10⁷= 38.7 000 000
we moved the decimal point seven places to the right and filled the empty spaces with zeros. This gives us the actual value of the number in standard form.
Scientific notation, also referred to as standard form or exponential notation, is a format for succinctly expressing very large or very tiny numbers. It is predicated on the notion that a number can be represented as the result of a coefficient and a multiple of 10.
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What is the molarity of 30.0 mL of hydrochloric acid solution after 15.0 mL of a 3.00 M solution has been diluted?
___ M (Answer Format X.X)
Answer:
the resulting solution is 1.5 M.
Explanation:
To solve this problem, we can use the dilution formula:
M1V1 = M2V2
where M1 is the initial concentration, V1 is the initial volume, M2 is the final concentration, and V2 is the final volume.
We are given that 15.0 mL of a 3.00 M hydrochloric acid solution has been diluted, and we want to find the molarity of the resulting solution. Let's use M1 for the initial concentration, V1 for the initial volume, M2 for the final concentration, and V2 for the final volume.
M1 = 3.00 M
V1 = 15.0 mL
V2 = 30.0 mL (since 15.0 mL has been diluted to 30.0 mL, the final volume is 30.0 mL)
We can rearrange the dilution formula to solve for M2:
M2 = (M1V1) / V2
Substituting the given values, we get:
M2 = (3.00 M x 15.0 mL) / 30.0 mL
M2 = 1.50 M
Therefore, the molarity of the resulting solution is 1.5 M.
How do mitosis and meiosis differ
Answer:Mitosis is the process in which a single cell divides to form two identical cells, while meiosis is a type of cell division that results in four daughter cells with half the number of chromosomes as the parent cell.
Explanation:
Which of the following would BEST describe an acid with a pH of 1?
Since it has a large concentration of hydrogen ions (H+) and a low concentration of hydroxide ions, an acid with a pH of 1 would be categorised as a strong acid. (OH-).
Is a pH of one corrosive strong?At the kinds of amounts you typically use in the lab, strong acids like hydrochloric acid have a pH between 0 and 1. At a quantity of 38%, hydrochloric acid (HCL) has a pH value of 1.1.
What is HCl's pH?Muriatic acid is another name for hydrochloric acid. It has an unpleasant scent and is colorless. As an acidifying substance, it is employed. Since it is a powerful acid, its pH will be lower than 7. There is a pH spectrum of 1.5 to 3.5.
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Is “Does eating less fat increase a mouse’s life span” a good scientific question?
What is the working mechanism in the pH meter? Briefly describe it.
A student mixes four reagents together, thinking that the solu- tions will neutralize each other. The solutions mixed together are 50.0 mL of 0.100 M hydrochloric acid, 100.0 mL of 0.200 M of nitric acid, 500.0 mL of 0.0100 M calcium hydroxide , and 200.0 mL of 0.100 M rubidium hydroxide . Is the resulting solution neutral ? If not , calculate the concentration of excess H^+ or OH ions left in solution.
To determine whether the resulting solution is neutral, we need to calculate the moles of H+ and OH- ions present in the solution and compare their concentrations.
First, we can calculate the moles of H+ ions present in the solution by using the equation:
moles H+ = volume (L) x concentration (mol/L)
moles H+ = (50.0 mL + 100.0 mL) x 0.100 mol/L = 15.0 x 10⁻³ mol
Next, we can calculate the moles of OH- ions present in the solution by using the equation:
moles OH- = volume (L) x concentration (mol/L)
moles OH- = (500.0 mL + 200.0 mL) x 0.0100 mol/L = 7.0 x 10⁻³ mol
Since the number of moles of H+ and OH- ions are not equal, the resulting solution is not neutral. To calculate the concentration of excess H+ or OH- ions left in solution, we need to determine which ion is present in excess.
Since HCl and HNO3 are strong acids and Ca(OH)2 and RbOH are strong bases, we can assume that all of the H+ and OH- ions from the acids and bases will react completely to form water. Therefore, we can calculate the excess H+ or OH- ions by comparing the moles of H+ and OH- ions present in the solution.
moles H+ - moles OH- = (15.0 x 10⁻³mol) - (7.0 x 10⁻³ mol) = 8.0 x 10⁻³ mol
Since the moles of H+ ions are greater than the moles of OH- ions, there is an excess of H+ ions in the solution. To calculate the concentration of excess H+ ions, we can divide the moles of H+ ions by the total volume of the solution in liters:
[H+] = moles H+ / volume (L)
[H+] = 8.0 x 10⁻³ mol / (50.0 mL + 100.0 mL + 500.0 mL + 200.0 mL) = 3.2 x 10⁻⁴M
Therefore, the resulting solution is not neutral, and it has an excess of H+ ions with a concentration of 3.2 x 10⁻⁴ M.
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Pls help me in this question in chemistry parts 6_10_11_13
Answer:
i am adding solution with attachment
Explanation:
I NEED ASAPPP
How many moles of bromine gas would occupy a volume of 20 L at a pressure of .90 atm and a temperature of 90°C? Show all work.
R= 8.31 L kPa/K mol
1 atm=101.3kPa
0.0652 moles of bromine gas would occupy a volume of 20 L at a pressure of 0.90 atm and a temperature of 90°C.
To solve this problem, we can use the ideal gas law:
PV = nRT
where P is the pressure, V is the volume, n is the number of moles, R is the ideal gas constant, and T is the temperature in Kelvin.
First, we need to convert the temperature from Celsius to Kelvin by adding 273.15:
T = 90°C + 273.15 = 363.15 K
Next, we need to convert the pressure from atm to kPa:
0.90 atm x 101.3 kPa/atm = 91.17 kPa
Now we can plug in the values we have:
n = (PV) / (RT)
n = (91.17 kPa x 20 L) / (8.31 L kPa/K mol x 363.15 K)
n = 0.0652 mol.
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Draw the MO diagram for the superoxide ion, O2-. Which statement is true regarding the superoxide ion?
A. The superoxide ion is diamagnetic.
B. It is attracted to a magnetic field.
C. Its MO diagram has two unpaired electrons.
D. It has a bond order of 2.
A. The superoxide ion is diamagnetic.
This statement is false. According to Hund's rule, electrons prefer to occupy separate orbitals if possible, which means that the two unpaired electrons in the π* orbital will have parallel spins, making the superoxide ion paramagnetic.
B. It is attracted to a magnetic field.
This statement is true. As a paramagnetic species, the superoxide ion will be attracted to a magnetic field.
C. Its MO diagram has two unpaired electrons.
This statement is true. The π* orbital contains two electrons with parallel spins, which means they are unpaired.
D. It has a bond order of 2.
This statement is also true. The bond order can be calculated by taking the difference between the number of electrons in the bonding orbitals (σ and π) and the number of electrons in the antibonding orbitals (σ* and π*), and then dividing by two. In this case, the bonding orbitals have 6 electrons and the antibonding orbitals have 4 electrons, giving a bond order of 1. (6 - 4) / 2 = 1. However, because the superoxide ion is a radical species with unpaired electrons, we need to add one more electron to the MO diagram to get the correct bond order. The total number of valence electrons in the superoxide ion is 16 (6 from each oxygen atom, plus the extra electron), which gives a bond order of 2. (8 - 6) / 2 = 1.
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What would be the destiny (in g/L) of a sample of C2H2Cl2 gas at 70.0C and 2.50 atm of pressure
The density of the gas would be 9.01 g/L.
To calculate the density (in g/L) of a gas, we can use the ideal gas law:
PV = nRT
where P is the pressure, V is the volume, n is the number of moles of gas, R is the gas constant, and T is the temperature in Kelvin.
To solve for n/V (the number of moles of gas per unit volume), we can rearrange the ideal gas law:
n/V = P/RT
The density (in g/L) is then equal to the molar mass (in g/mol) times n/V:
density = (molar mass) * (n/V)
The molar mass of C₂H₂Cl₂ is:
2(12.01 g/mol) + 2(1.01 g/mol) + 2(35.45 g/mol) = 96.93 g/mol
To use the ideal gas law, we need to convert the temperature to Kelvin:
70.0C + 273.15 = 343.15 K
Plugging in the values:
P = 2.50 atm
V = unknown (we are not given the volume)
n/V = P/RT = 2.50 atm / (0.08206 Latm/(molK) * 343.15 K) = 0.0930 mol/L
molar mass = 96.93 g/mol
Therefore, the density of the C₂H₂Cl₂ gas at 70.0C and 2.50 atm of pressure is:
density = (molar mass) * (n/V) = 96.93 g/mol * 0.0930 mol/L = 9.01 g/L.
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how electrons remain in pairs form however they contain similar charge
The charge of electrons is determined by their spin, which is either up or down and the same spin will repel each other due to their negative charge, while electrons with opposite spins will attract each other.
Electrons are negatively charged particles and exist in pairs because of the Pauli Exclusion Principle, which states that no two electrons in an atom can have the same set of quantum numbers. This means that if two electrons are in the same atom, they must have different energy levels, angular momenta, and magnetic moments. This prevents the electrons from occupying the same space and prevents them from having the same charge. As a result, electrons remain in pairs, even though they have the same charge.
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how many moles of carbon atoms are there in 0.388 mole of c2h6?
The chemical formula for C2H6 tells us that there are two carbon atoms in each molecule of ethane. Therefore, to find the number of moles of carbon atoms in 0.388 moles of C2H6, we can use the following steps:
1. Determine the total number of moles of carbon atoms in 0.388 moles of C2H6 by multiplying the number of moles of C2H6 by the number of carbon atoms per molecule:
0.388 moles C2H6 x 2 moles C / 1 mole C2H6 = 0.776 moles C
2. Round the result to the appropriate number of significant figures, if necessary.
Therefore, there are 0.776 moles of carbon atoms in 0.388 moles of C2H
i need a lab report! anyone have the chart with what they wrote and the answers to the lab report. Lab: Ionic and Covalent Bonds Write a lab report for this lesson’s lab. Be sure that your report: includes all major elements of a lab report. meets your teacher’s content and format expectations. is clearly organized and formatted. demonstrates strong scientific reasoning and writing.
Ionic and Covalent Bonds- The materials utilized during the experiment, the steps taken, and the techniques used to analyze the results should all be described in the section titled "Materials and Methods."
How do you write a chemistry lab report?A lab report is broken down into eight sections: title, abstract, introduction, techniques and materials, results, discussion, conclusion, and references. The title of the lab document must be descriptive of the scan and replicate what the scan analyzed.
What are ionic and covalent compounds in chemistry lab?Ionic bonds require an electron donor, the metal, and an electron accepter, the non-metal. Covalent bonding is the sharing of electrons between atoms. This kind of bonding happens between two of the equal element or elements shut to each other in the periodic table.
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Can somebody please help me solve this? I would very much appreciate it.
a. Balanced equation for the decomposition of sodium bicarbonate by heating is:
2 NaHCO3(s) → Na2CO3(s) + CO2(g) + H2O(g)
b. To heat the mixture, the student can use a Bunsen burner or a hot plate in a fume hood to prevent the release of any harmful gases. The mixture should be heated until there is no more mass loss. To determine the mass loss, the student can weigh the vial and its contents before and after heating. The difference between the two weights will be the mass loss.
c. The student can know that all the sodium bicarbonate has been decomposed when there is no more mass loss. The heating should be continued until the mass of the vial and its contents remains constant.
d. The mass loss of 2.28 g is due to the decomposition of 1 mol of NaHCO3, which has a molar mass of 84 g/mol. Therefore, the original mixture contained 2.28/84 = 0.027 mol of NaHCO3. The mass of Na2CO3 in the mixture can be calculated as follows:
mass of Na2CO3 = mass of mixture - mass loss = 14.00 g - 2.28 g = 11.72 g
The molar mass of Na2CO3 is 106 g/mol, so the number of moles of Na2CO3 in the mixture is:
moles of Na2CO3 = mass of Na2CO3/molar mass of Na2CO3 = 11.72 g/106 g/mol = 0.111 mol
The percentage of Na2CO3 in the original mixture is:
% Na2CO3 = (moles of Na2CO3/total moles of carbonate) x 100% = (0.111/0.138) x 100% = 80.4%
e. To determine which is the limiting reactant, we need to compare the number of moles of NaHCO3 and Na2CO3 in the mixture. We know that the mixture contained 0.027 mol of NaHCO3 and 0.111 mol of Na2CO3. Since the balanced equation shows that 2 moles of NaHCO3 produce 1 mole of Na2CO3, the number of moles of Na2CO3 that can be produced from 0.027 mol of NaHCO3 is:
moles of Na2CO3 = 0.027 mol NaHCO3 x (1 mol Na2CO3/2 mol NaHCO3) = 0.0135 mol Na2CO3
Since the actual amount of Na2CO3 in the mixture is greater than 0.0135 mol, we can conclude that NaHCO3 is the limiting reactant, and Na2CO3 is in excess.
d.
Mass of NaHCO3 = 2.28 g / 84 g/mol = 0.027 mol NaHCO3
Mass of Na2CO3 = 14.00 g - 2.28 g = 11.72 g
Moles of Na2CO3 = 11.72 g / 106 g/mol = 0.111 mol Na2CO3
Total moles of carbonate = moles of NaHCO3 + moles of Na2CO3 = 0.027 mol + 0.111 mol = 0.138 mol
% Na2CO3 = (moles of Na2CO3 / total moles of carbonate) x 100% = (0.111 mol / 0.138 mol) x 100% = 80.4%
e.
Moles of Na2CO3 that can be produced from 0.027 mol of NaHCO3 = 0.027 mol NaHCO3 x (1 mol Na2CO3 / 2 mol NaHCO3) = 0.0135 mol Na2CO3
Since the actual amount of Na2CO3 in the mixture (0.111 mol) is greater than 0.0135 mol, NaHCO3 is the limiting reactant, and Na2CO3 is in excess.
ChatGPT
How much is evolved/absorbed (answer is ______ ) when 444 g of NBr3 is produced?
The amount of energy evolved/absorbed when 444 grams of NBr₃ is produced is 38.5 KJ
How do i determine the energy evolved/absorbed?First, we shall determine the number of mole in 444 grams of NBr₃. Details below:
Mass of CaCl₂ = 444 grams Molar mass of NBr₃ = 253.719 g/mol Mole of NBr₃ =?Mole = mass / molar mass
Mole of NBr₃ = 444 / 253.719
Mole of NBr₃ = 1.75 mole
Finally, we shall determine the energy evolved/absorbed. Details below:
N₂ + 3Br₂ -> 2NBr₃ + 44 KJ
From the balanced equation above,
When 2 moles of NBr₃ were produced, 44 KJ of heat energy were absorbed.
Therefore,
When 1.75 moles of NBr₃ is produced, = (1.75 × 44) / 2 = 38.5 KJ of heat is absorbed.
Thus, the heat energy absorbed is 38.5 KJ
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What are the common reducing agent
Answer: might be lack of taste, education, and good manners
Explanation:
A solution has a volume of 250 mL and has the molarity of 2.4 M NaCl. How many moles of NaCl are in the solution?
There are 0.6 moles of sodium chloride in a 250 mL solution with a molarity of 2.4 M sodium chloride.
In 250 mL of a 0.5 M NaCl solution, how many moles of sodium chloride are there?This leads us to the conclusion that a 250 mL solution of a 0.5 M sodium chloride contains 0.125 moles and 7.32 grammes of sodium chloride, respectively.
250 mL of a 0.4 M solution contains how many moles of sodium chloride?A solution with a concentration of 0.4 M contains 0.4 moles of solute per litre of solution. By utilising dimensional analysis, you may calculate how many moles of solute are present in 250 mL of the solution. litre and millilitre units
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2 FeCl3 + 3 Pb(NO3)3 -> 2 Fe(NO3)3 + 3 PbCl₂
How many mol of Fe(NO3)3 will be produced by using 1.5 mol of Pb(NO3)3?
Need help on 9 and 10
a) The balanced chemical equation is: 2Al + 3ZnCl₂ → 2AlCl₃ + 3Zn. To determine the number of moles of ZnCl₂ required, we need to first calculate the number of moles of Al using its molar mass:
molar mass of Al = 26.98 g/mol
moles of Al = 17.8 g / 26.98 g/mol = 0.660 mol
According to the balanced equation, 2 moles of Al react with 3 moles of ZnCl₂. Therefore, we can use a proportion to find the number of moles of ZnCl₂:
0.660 mol Al / 2 mol Al = x mol ZnCl₂ / 3 mol ZnCl₂
x mol ZnCl₂ = (0.660 mol Al × 3 mol ZnCl₂) / 2 mol Al = 0.990 mol ZnCl₂
Therefore, 0.990 moles of ZnCl₂ are required.
b) From the balanced equation, we see that 2 moles of Al produce 2 moles of AlCl₃ and 3 moles of Zn. We can use the molar masses of the products to calculate the amount of each product produced:
molar mass of AlCl₃ = 133.34 g/mol
moles of AlCl₃ produced = 2 mol Al × (133.34 g/mol) / (26.98 g/mol) = 9.88 mol AlCl₃
molar mass of Zn = 65.38 g/mol
moles of Zn produced = 3 mol Zn × (65.38 g/mol) / (1 mol Zn) = 196.14 g Zn / 65.38 g/mol = 3.00 mol Zn
Therefore, 9.88 moles of AlCl₃ and 3.00 moles of Zn are produced.
c) The balanced chemical equation is: Fe₂O₃ + 3CO → 2Fe + 3CO₂
To determine the number of moles of CO needed to react with 4.00 kg of Fe₂O₃, we need to first convert the mass of Fe₂O₃ to moles using its molar mass:
molar mass of Fe₂O₃ = 159.69 g/mol
moles of Fe₂O₃ = 4.00 kg / (1000 g/kg) / 159.69 g/mol = 0.0250 mol
According to the balanced equation, 3 moles of CO react with 1 mole of Fe₂O₃. Therefore, we can use a proportion to find the number of moles of CO:
0.0250 mol Fe₂O₃ / 1 mol Fe₂O₃ = x mol CO / 3 mol CO
x mol CO = 0.0250 mol Fe₂O₃ × 3 mol CO / 1 mol Fe₂O₃ = 0.0750 mol CO
Therefore, 0.0750 moles of CO are needed.
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We wish to
determine how
many moles of
barium sulfate
form when 50.0
mL of 0.250 M
aluminum
mol Al₂(SO),
Resources
sulfate reacts
with excess
barium nitrate.
3Ba(NO3)2(aq) + Al₂(SO4)3(aq)
How many
moles of
Al₂(SO4)3 are
present
in 50.0 mL of
0.250 M
Al₂(SO4)3?
Enter
Help
To determine the number of moles of Al₂(SO₄)₃ present in 50.0 mL of 0.250 M Al₂(SO₄)₃, we need to use the formula relating molarity to moles and volume.
What is a mole and how do you calculate the moles of Al₂(SO₄)₃ present?In chemistry, a mole is a unit of measurement used to show the measure of a chemical entity. One mole of a substance is defined as the amount of that substance that contains the same number of particles, such as atoms, molecules, or ions, as there are atoms in exactly 12 grams of carbon-12.
To determine the number of moles of Al₂(SO₄)₃ present in 50.0 mL of 0.250 M Al₂(SO₄)₃ , we need to use the formula:
Molarity (M) = moles (n) / volume (V)
Rearranging the formula, we get:
n= M*V
First, let's convert the volume of 50.0 mL to liters:
50.0 mL = 50.0 x 10⁻³ L
Next, we can substitute the given values into the formula:
moles of Al₂(SO₄)₃ = 0.250 M x 50.0 x 10⁻³ L
moles of Al₂(SO₄)₃ = 0.0125 mol
Therefore, there are 0.0125 moles of Al₂(SO₄)₃ present in 50.0 mL of 0.250 M Al₂(SO₄)₃.
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help me plssss i beg i beg
To calculate the percent yield, we need to compare the actual yield obtained to the theoretical yield that could be obtained under ideal conditions.
First, we need to find the balanced chemical equation for the reaction:
2 Cu + S → Cu2S
From the equation, we see that 2 moles of copper are needed to produce 1 mole of copper(1) sulfide.
Given that 0.0970 moles of copper was used, the theoretical yield of copper(1) sulfide can be calculated as follows:
1 mol Cu2S = 2 × 63.55 g Cu + 32.07 g S = 159.17 g Cu2S
0.0970 mol Cu × (159.17 g Cu2S / 2 mol Cu) = 7.94 g Cu2S (theoretical yield)
The actual yield obtained is given as 2.64 g Cu2S. Therefore, the percent yield can be calculated as:
percent yield = (actual yield / theoretical yield) × 100%
percent yield = (2.64 g / 7.94 g) × 100%
percent yield = 33.2%
The percent yield for the reaction is 33.2%. This means that only 33.2% of the expected yield of copper(1) sulfide was obtained under the given conditions.
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Predicting Products: Ga2S3 + CaBr2. (2 and 3 are coefficients)
(if you could just write it out it’d be helpful)
The product of Ga₂S₃ + CaBr₂ is CaS and GaBr₃ , where 2 and 3 are stoichiometric coefficients. The balanced chemical reaction is 2Ga₂S₃ + 6CaBr → 6CaS + 2GaBr₃. The sum of the coefficients is 5.
What is balanced chemical reaction?An equation for a chemical reaction is said to be balanced if both the reactants and the products have the same number of atoms and total charge for each component of the reaction. In other words, both sides of the reaction have an equal balance of mass and charge.
The reactants and products of a chemical reaction are listed in an imbalanced chemical equation, but the amounts necessary to meet the conservation of mass are not specified. For instance, the mass balance of the following equation for the reaction between iron oxide and carbon to produce iron and carbon dioxide is off:
Fe₂O₃ + C → Fe + CO₂
The equation must be balanced so that each type of atom appears in equal amounts on both the left and right sides of the arrow. This is accomplished by altering the compounds' coefficients (numbers placed in front of compound formulas). In this example, the subscripts (tiny numbers to the right of some atoms, including iron and oxygen) are never altered. The chemical identification of the compound would change if the subscripts were changed.
2 Fe₂O₃ + 3 C → 4 Fe + 3 CO₂
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How many grams of dry NH4Cl need to be added to 2.50 L of a 0.300 M solution of ammonia, NH3 , to prepare a buffer solution that has a pH of 8.51? Kb for ammonia is 1.8×10−5 .
The correct answer To prepare a buffer solution with a pH of 8.51, we need to use the Henderson-Hasselbalch equation:
pH = pKa + log([base]/[acid] where pKa is the dissociation constant for the base, [base] is the concentration of the base, and [acid] is the concentration of the conjugate acid. For the ammonia/ammonium ion buffer system, the equation is: NH3 + H2O ⇌ NH4+ + OH- The equilibrium constant expression for this reaction is: Kb = [NH4+][OH-]/[NH3] We are given the Kb value as 1.8 x 10^-5, and we can use it to find the concentration of OH- in the buffer solution: Kb = [NH4+][OH-]/[NH3] 1.8 x 10^-5 = [NH4+][OH-]/(0.300 - [NH4+]) Let's assume that the concentration of NH4+ is much less than 0.300 M (which is a reasonable assumption for most buffer solutions). This means that we can approximate the denominator as 0.300 M: 1.8 x 10^-5 = [NH4+][OH-]/0.300 Solving for [OH-], we get: [OH-] = sqrt(Kb*[NH3]) = sqrt(1.8 x 10^-5 * 0.300) = 6.60 x 10^-4 M To find the concentration of NH4+, we can use the Henderson-Hasselbalch equation: pH = pKa + log([base]/[acid]) 8.51 = 9.25 + log([NH4+]/[NH3]) Solving for [NH4+]/[NH3], we get: [NH4+]/[NH3] = 10^(8.51-9.25) = 3.52 x 10^-2 Since we know that the total volume of the buffer solution is 2.50 L, we can use the molarity of NH3 to find the moles of NH3 in the solution: moles of NH3 = 0.300 M x 2.50 L = 0.75 mol We can then use the ratio of NH4+ to NH3 to find the moles of NH4+ in the solution: moles of NH4+ = (3.52 x 10^-2) x (0.75 mol) = 2.64 x 10^-2 mol Finally, we can use the molar mass of NH4Cl (53.49 g/mol) to find the mass of NH4Cl needed to prepare the buffer solution: mass of NH4Cl = moles of NH4Cl x molar mass of NH4Cl To find the moles of NH4Cl, we can use the stoichiometry of the reaction between NH4Cl and NH3: NH4Cl + NH3 → NH4+ + Cl- For every mole of NH4+ in the buffer solution, we need one mole NH4Cl. Therefore moles of NH4Cl = moles of NH4+ = 2.64 x 10^-2 molSubstituting this value into the equation for mass of NH4Cl, we getmass of NH4Cl = (2.64 x 10^-2 mol) x (53.49 g/mol) = 1.41 g Therefore, we need approximately 1.41 grams of dry NH4Cl to add to 2.50 L of a 0.300 M
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How many grams of O2 will forms when 4.6 molesof lead II oxide decomposes?
The correct answer is To answer this question, we need to use the balanced chemical equation for the decomposition of lead(II) oxide (PbO).
[tex]PbO(s) → Pb(s) + O2(g)[/tex]From this equation, we can see that for every 1 mole of PbO that decomposes, 1 mole of O2 is produced. Therefore, we can use the given number of moles of PbO to determine the number of moles of O2 produced, and then convert to grams using the molar mass of O2 We are given 4.6 moles of PbO, so we can calculate the moles of O2 produced as follows: moles of O2 = moles of PbO moles of O2 = 4.6 moles Now, we can use the molar mass of O2 to convert from moles to grams: mass of O2 = moles of O2 x molar mass of O2 mass of O2 = 4.6 moles x 32.00 g/mol mass of O2 = 147.2 g Therefore, when 4.6 moles of PbO decompose, 147.2 grams of O2 are produced. It's important to note that the given reaction assumes that the lead(II) oxide decomposes completely, meaning that all of the PbO is converted to Pb and O2. In reality, some of the PbO may not decompose completely, and other side reactions may occur. However, assuming complete decomposition, the calculated mass of O2 represents the theoretical yield of the reaction.
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Gaseous carbon monoxide reacts with hydrogen gas to form gaseous methane (CH4) and oxygen gas
The reaction requires a stoichiometric ratio of [tex]2:4[/tex] for carbon monoxide to hydrogen gas, resulting in the formation of methane and oxygen gas as products.
What is the balanced chemical equation?The balanced chemical equation for the reaction between gaseous carbon monoxide [tex](CO)[/tex] and hydrogen gas [tex](H_2)[/tex] to form gaseous methane [tex](CH_4)[/tex] and oxygen gas [tex](O_2)[/tex] is:
[tex]2CO(g) + 4H2(g) \rightarrow CH4(g) + O2(g)[/tex]
In this equation, [tex]2[/tex] moles of carbon monoxide react with [tex]4[/tex] moles of hydrogen gas to produce 1 mole of methane and [tex]1[/tex] mole of oxygen gas.
Therefore, The reaction requires a stoichiometric ratio of [tex]2:4[/tex] for carbon monoxide to hydrogen gas, resulting in the formation of methane and oxygen gas as products.
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The particle diagram below represents a solid sample of silver.
Ag
Ag
(Ag
Ag
N
Ag
2.
Ag
4.
(Ag
Ag
Ag
Ag
Ag
(Ag
1. metallic bonding
hydrogen bonding
3. covalent bonding
ionic bonding
Which type of bonding is present when valence electrons move within the sample?
The particle diagram represents a solid sample of silver, which is a metallic element. The type of bonding present when valence electrons move within the sample of silver is 1.) metallic bonding
What is metallic bonding?Metallic bonding is the type of bonding present in metals like silver, where valence electrons move freely throughout the solid sample. Therefore, the type of bonding present when valence electrons move within the sample of silver is metallic bonding.
Metallic bonding is a type of chemical bonding that occurs in metals and alloys. It is a type of bonding where valence electrons are not strongly bound to any one particular atom, but are free to move throughout the entire solid structure.
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How do ionic differ from covalent bonds?
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why is grass green why not pink or blue?
Answer:
There is a tint or pigment in the grass that gives it the color green called chlorophyll. That is used during the photosynthesis cycle.
Explanation:
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Formic acid has a Ka of 1.77*10^-4. To 55.0 mL of 0.25 M solution 75.0 of 0.12 M NaOH is added . What is the resulting pH.
Answer:
The first step is to determine the moles of formic acid and NaOH that react. moles of formic acid = (0.25 mol/L) x (0.055 L) = 0.01375 mol moles of NaOH = (0.12 mol/L) x (0.075 L) = 0.009 mol Since NaOH is a strong base, it will react completely with formic acid to form sodium formate and water: HCOOH + NaOH → HCOONa + H2O The limiting reagent in this case is NaOH, so all of it will be consumed in the reaction. The amount of excess formic acid that remains can be calculated: moles of HCOOH remaining = moles of HCOOH initial - moles of NaOH used moles of HCOOH
ENTHALPHY LAB QUESTIONS!!
PURPOSE OF EXPERIMENT: To find Heat of Solution of sodium hydroxide and to find the heat of neutralization between sodium hydroxide and hydrochloric acid.
Experiment 1 Procedure:
1. Measure 50.0 mL of water (tap) into a 100 mL graduated cylinder and pour it into a large coffee cup.
2. Determine the temperature of this water
3. Measure out 2.00 g of sodium hydroxide into a piece of paper towel *tare scale!
4. Add the sodium hydroxide to the water in the coffee cup and put a small cup over it, with the thermometer through the hole. Stir GENTLY with the thermometer and record the temperature every 30 seconds for 3 minutes or until it peaks. Record this in a properly labelled table.
5. Let this stand for 45 minutes before proceeding to Exp. 2.
WHAT WE FOUND IN EXP 1:
T (temp.) initial = 20 degrees C
T (temp) FINAL = 28.5 degrees C
moles of sodium hydroxide = 0.0518mol
the molar mass of sodium hydroxide = 39.969g/mol
C (specific heat of water) = 4.184J/g degrees C
THE NUMBER OF TRIALS FOR TEMP IN EXP 1
1st trial = 21 C
2nd trial = 24.5 C
3rd trial = 26 C
4th trial = 26 C
5th trial = 28 C
6th trial = 28.5 C
7th trial = 28.5 C (final temp)
ANALYSIS FOR EXPERIMENT ONE:
1. Determine the moles of sodium hydroxide (NaOH) from the experiment.
2. Determine Qsurroundings and Qrxn
3. Determine the enthalpy for the dissociation of sodium hydroxide (delta H sol)
4. Write the thermochemical equation for the dissociation of sodium hydroxide TWO ways and write an enthalpy diagram
5. What assumptions did you make to calculate #2? (some example assumptions to make: assume that the solution is water and that heat and density COULD be the same as water, etc)
6. Research the actual value and determine the percent error
7. In terms of bonds breaking and forming, what is RESPONSIBLE FOR ENTHALPY CHANGE?
EXPERIMENT 2 PROCEDURE:
1. Measure out 50.0 mL of 0.75 concentration M HCl into a graduated cylinder
2. Measure and record the temperature of the sodium hydroxide solution from exp. 1.
3. Add the hydrochloric acid solution to the sodium hydroxide solution, put the small cup on, and record the temperature change every 15 seconds for 1 minute. Stir GENTLY. Record this in a properly labelled table (will be given below)
4. Solutions can be discarded down the sink.
WHAT WE FOUND IN EXP. 2:
T (temp) initial = 23.5 C
T (temp) FINAL = 27 C
THE NUMBER OF TRIALS FOR TEMP IN EXP 2
1st trial = 27 C
2nd trial = 27 C
3rd trial = 27 C
4th trial = 27 C (FINAL TEMP)
ANALYSIS FOR EXPERIMENT 2:
1. Determine the moles of HCl added to this mixture
2. Write the chemical equation for this reaction
3. Determine the limiting reagent
4. Determine the Qsurr and Qrxn *CONVERT TO kJ*
5. Determine the enthalpy for the neutralization reaction.
6. Write the thermochemical equation for the dissociation of sodium hydroxide TWO WAYS and write an enthalpy diagram
7. Research the actual value and determine the percent error.
8 Explain sources of experimental error for both experiments and BE SPECIFIC! (NOT CALCULATION ERRORS, SPILLING, OR LOSING REACTANTS - DO NOT COUNT AS ERRORS! They can be EXPERIMENTAL due to heat loss/gain, room temp *specific heat capacity is for 25 C*, and atmospheric pressure is constant. And they can be MEASUREMENTS - consider the precision and the potential range of error for each measurement)
9. In terms of bonds breaking and forming, what's responsible for the enthalpy change?
CONCLUSION: write a brief statement that refers to the purpose.
In Experiment 1, we found the heat of solution of sodium hydroxide (NaOH) by dissolving 2.00 g of NaOH in 50.0 mL of water.
What was observed in the experiment?The temperature rose from 20°C to 28.5°C. The moles of NaOH were determined to be 0.0518 mol.
Using the specific heat of water (4.184 J/g°C), we calculated the enthalpy change (ΔH_sol) and compared it to the literature value, finding a percent error.
In Experiment 2, we measured the heat of neutralization between NaOH and 0.75 M HCl.
The temperature increased from 23.5°C to 27°C. We determined the moles of HCl, limiting reagent, and enthalpy change (ΔH_neut) for the neutralization reaction.
The actual value was compared to the literature value, and percent error was calculated.
Experimental errors in both experiments could arise from heat loss/gain, variations in room temperature and atmospheric pressure, and imprecise measurements.
The enthalpy changes in both experiments are due to bond breaking and forming during the dissociation of NaOH and the neutralization reaction between NaOH and HCl.
In conclusion, we determined the heat of solution for sodium hydroxide and the heat of neutralization between sodium hydroxide and hydrochloric acid, and analyzed the possible sources of experimental errors.
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