Question 1

The chemical reaction occurring during the discharge of a lead storage battery can be represented by the equation: Pb(s) + PbO₂(s) +2 H₂SO₄(aq) → 2 PbSO₄(s) + 2 H₂O(l) Which is the limiting reagent and the amount of PbSO₄ produced if 53.0 g of Pb, 77.3 g of PbO₂, and 534 mL of 0.544 M solution of H₂SO₄ is used?

Accepted Answer

The limiting reagent is H₂SO₄, and the amount of PbSO₄ produced is 88.1 g.

Question 2

What is the molarity of methanol, CH₃OH (d = 0792 g/mL), if 150.0 mL is dissolved in enough water to make 4.00 L of solution?

Accepted Answer

The answer of What is the molarity of methanol, CH₃OH...

Question 3

What is the molarity of a sucrose solution (C₁₂H₂₂O₁₁) if 110.0 g of a 92.0% pure solid is dissolved per 250.0 mL of water?

Accepted Answer

The answer of What is the molarity of a sucrose...

Question 4

"Washing soda" (sodium carbonate) may be used to "soften" water by the removal of certain ions that would otherwise react with common soaps. When the "hardness" is due to calcium ion, the "softening" process may be represented as: Ca²⁺(aq) + CO₃^2-(aq) → CaCO₃(s) What mass of sodium carbonate would be required to remove essentially all of the calcium ion from 750 L of solution containing 43 mg Ca²⁺ per liter?

Accepted Answer

The correct answer is A because 85 g of sodium carbonate would be required to remove essentially all of the calcium ion from 750 L of solution containing 43 mg Ca2+ per liter.

Question 5

What mass of oxygen gas would be consumed by the complete combustion of 7.5 g of a mixture of propane (C₃H₈) and butane (C₄H₁₀) in the mole ratio of C₃H₈/C₄H₁₀ = 1.33?

Accepted Answer

The answer of What mass of oxygen gas would be...

Question 6

What is the molarity of formaldehyde in a solution containing 0.25 g of formaldehyde (CH₂O) per mL?

Accepted Answer

To calculate molarity (M), we need to know the number of moles of solute (n) and volume of solution (V) in liters.

First, we need to calculate the number of moles of formaldehyde in 1 mL of solution:

Number of moles = mass in grams / molar mass
Molar mass of formaldehyde (CH2O) = 12.01 + 2(1.01) + 16.00 = 30.03 g/mol

Number of moles = 0.25 g / 30.03 g/mol = 0.00833 mol

Since the volume of solution is given as 1 mL, we have:

V = 1 mL / 1000 mL/L = 0.001 L

Now we can calculate the molarity:

Molarity = moles / volume
Molarity = 0.00833 mol / 0.001 L = 8.3 M

Therefore, the answer is C.

Question 7

What is the sum of the coefficients when the following is balanced with the smallest integer coefficients? CH₃OH → CO + H₂

Accepted Answer

The answer of What is the sum of the coefficients...

Question 8

How much Cl₂, in g, is required to produce 12.0 g CCl₄ according to the following reaction? CH₄ + 4 Cl₂ → CCl₄ + 4 HCl

Accepted Answer

To find the mass of Cl₂ needed, first calculate the moles of CCl₄ produced: 12.0 g CCl₄ / 153.8 g/mol = 0.078 moles. According to the balanced equation, 4 moles of Cl₂ are needed per mole of CCl₄, so 0.078 moles CCl₄ x 4 moles Cl₂/mole CCl₄ = 0.312 moles Cl₂. The molar mass of Cl₂ is 70.9 g/mol, so 0.312 moles x 70.9 g/mol = 22.1 g Cl₂.

Question 9

You have 10.00 L of a 0.350 M KCl solution, but you need a solution that is 0.450 M. What volume of water, in L, would you evaporate from the solution?

Accepted Answer

To concentrate a solution from 0.350 M to 0.450 M without adding more solute, you need to evaporate some of the solvent. The amount of KCl in the original solution is the volume times the concentration, which is $10.00 \, \text{L} \times 0.350 \, \text{M} = 3.50 \, \text{mol}$. To achieve a concentration of 0.450 M with the same amount of KCl, you can set up the equation $3.50 \, \text{mol} = 0.450 \, \text{M} \times V$, where $V$ is the final volume of the solution. Solving for $V$ gives $V = \frac{3.50}{0.450} = 7.78 \, \text{L}$. To find the volume of water evaporated, subtract the final volume from the initial volume: $10.00 \, \text{L} - 7.78 \, \text{L} = 2.22 \, \text{L}$.

Question 10

What mass of water is produced in the metathesis reaction 75.2 g Zn(OH)₂ with 43.4 g HCl?

Accepted Answer

The answer of What mass of water is produced in...

Question 11

What is the sum of the coefficients when the following equation is balanced with the smallest integer coefficients? H₂SO₃ + Al(OH)₃ → Al₂(SO₃)₃ + H₂O

Accepted Answer

The answer of What is the sum of the coefficients...

Question 12

The molarity of a solution that contains 14.7 g of H₂SO₄ in 200.0 mL solution is ________.

Accepted Answer

The answer of The molarity of a solution that contains...

Question 13

The chemical reaction during low current discharge of a simple "dry cell" involves: (unbalanced) Zn + MnO₂ + NH₄Cl → ZnCl₂ + Mn₂O₃ + NH₃ + H₂O What is the coefficient for zinc in the balanced equation that uses the lowest whole number ratios, and what is the limiting reagent for a process in which equal masses of reactants are mixed?

Accepted Answer

The answer of The chemical reaction during low current discharge...

Question 14

The chemical reaction occurring during the discharge of a lead storage battery can be represented by the equation: Pb(s) + PbO₂(s) + 2 H₂SO₄(aq) → 2 PbSO₄(s) + 2 H₂O(l) What mass of lead sulfate would result from the complete reaction of 41.4 g of lead?

Accepted Answer

The answer of The chemical reaction occurring during the discharge...

Question 15

If an aqueous solution containing 46 g of sodium carbonate per liter is mixed with an equal volume of 0.20 M aqueous hydrochloric acid, what would be the molarity of sodium chloride in the final solution, assuming volumes were additive?

Accepted Answer

The answer of If an aqueous solution containing 46 g...

Question 16

Write the complete balanced equation for the complete combustion reaction expected to occur between C₃H₇OH and O₂.

Accepted Answer

The complete combustion of propanol (C3H7OH) with oxygen (O2) produces carbon dioxide (CO2) and water (H2O). The balanced equation is: 2 C3H7OH + 9 O2 → 6 CO2 + 8 H2O.

Question 17

Our task is to measure the volume of blood in an elephant. One way to do this would be to drain its blood into a suitable container. Aside from harmful side effects which this method has on the elephant, it will not be successful, as blood will still remain behind in the tissues. Hence, we will inject 2.00 ml of a 2.00 M solution of a dye which the elephant will not appreciably metabolize or excrete in one hour and then measure the concentration of this dye in the bloodstream (our sample being taken from another leg than the point of injection) after 30 minutes, a sufficient time to thoroughly mix the dye in the bloodstream. The concentration of dye at this point is 1.25 x 10^-5 M. What is the volume of blood in the elephant?

Accepted Answer

The volume of blood in the elephant can be calculated using the formula:Volume of blood = (Volume of dye injected * Concentration of dye injected) / Concentration of dye in bloodstreamVolume of dye injected = 2.00 mlConcentration of dye injected = 2.00 MConcentration of dye in bloodstream = 1.25 x 10^-5 MVolume of blood = (2.00 ml * 2.00 M) / 1.25 x 10^-5 M = 320 LTherefore, the volume of blood in the elephant is 320 L.

Question 18

Given the reaction: 2 KMnO₄ + 10 KI + 8 H₂SO₄ → 6 K₂SO₄ + 2 MnSO₄ + 5 I₂ + 8 H₂O How many moles of I2 are produced by reacting 28.0 g KMnO₄, 18.0 g KI, and 46.0 g H₂SO₄?

Accepted Answer

First, we need to convert the given masses into moles using their molar masses:
- KMnO4: 28.0 g / 158.03 g/mol = 0.177 mol
- KI: 18.0 g / 166.00 g/mol = 0.108 mol
- H2SO4: 46.0 g / 98.08 g/mol = 0.469 mol

Now, we can use the stoichiometry of the reaction to determine the limiting reagent (the reactant that will be completely consumed) and the amount of I2 produced:

- From the balanced equation, we can see that 2 moles of KMnO4 react with 10 moles of KI to produce 5 moles of I2.
- The mole ratio of KMnO4 to KI is 2:10 = 1:5, which means that the limiting reagent is KMnO4 because we have less of it compared to what is needed to react with all of the KI.
- Using the mole ratio of KMnO4 to I2, we can calculate how many moles of I2 will be produced:
0.177 mol KMnO4 x (5 mol I2 / 2 mol KMnO4) = 0.443 mol I2

Therefore, the answer is B) 0.0542 mol.

Question 19

What mass of MgCl₂ in grams must be added to 250.0 mL of a 0.25 M MgCl₂ solution to produce a 0.40 M solution, assuming no change of volume upon addition?

Accepted Answer

First, we can use the formula for dilution to determine how much MgCl2 is needed to make the new solution:

M1V1 = M2V2

Where M1 = 0.25 M, V1 = 250.0 mL, M2 = 0.40 M, and V2 = the total volume of the new solution (which we assume is the same as the initial volume, 250.0 mL):

(0.25 M)(250.0 mL) = (0.40 M)(250.0 mL + x)

Solving for x, we get:

x = 90.0 mL

So we need to add 90.0 mL of MgCl2 to the initial solution.

To convert mL to grams, we need to use the density of the solution. The density of a 0.25 M MgCl2 solution is approximately 1.06 g/mL, so 90.0 mL of the solution has a mass of:

90.0 mL x 1.06 g/mL = 95.4 g

However, we only need to add MgCl2, not the entire solution. The molar mass of MgCl2 is 95.21 g/mol, so 95.4 g of the solution contains:

95.4 g / 95.21 g/mol = 1.001 mol MgCl2

Finally, we can use the molarity of the initial solution to determine the number of moles of MgCl2 in the 250.0 mL of solution:

0.25 M x 0.2500 L = 0.0625 mol MgCl2

To make a 0.40 M solution, we need a total of:

(0.40 M)(0.2500 L) = 0.1000 mol MgCl2

So we need to add:

0.1000 mol MgCl2 - 0.0625 mol MgCl2 = 0.0375 mol MgCl2

of MgCl2. Since we know that 1.001 mol of MgCl2 is present in 95.4 g of the solution, we can find the mass of MgCl2 needed:

0.0375 mol MgCl2 x (95.21 g/mol) = 3.54 g MgCl2

This corresponds to answer choice D.

Question 20

To measure the volume of an irregularly shaped container filled with water, 1.00 mL of 2.00 M potassium chloride solution is added. After stirring, a 5.00 mL sample was found to contain 2.54 × 10^-2 mg of potassium ion. What is the volume of the container?

Accepted Answer

The concentration of the potassium chloride solution before dilution is:$$C_1 = 2.00 	ext{ M}$$The volume of the potassium chloride solution added is:$$V_1 = 1.00 	ext{ mL}$$The concentration of the potassium chloride solution after dilution is:$$C_2 = \frac{C_1V_1}{V_2}$$where V2 is the volume of the container.The mass of potassium ion in the 5.00 mL sample is:$$m = 2.54 	imes 10^{-2} 	ext{ mg}$$The moles of potassium ion in the 5.00 mL sample is:$$n = \frac{m}{M}$$where M is the molar mass of potassium ion (39.10 g/mol).The volume of the container is:$$V_2 = \frac{C_1V_1}{C_2}$$$$V_2 = \frac{(2.00 	ext{ M})(1.00 	ext{ mL})}{2.54 	imes 10^{-2} 	ext{ mg} / 5.00 	ext{ mL} 	imes 39.10 	ext{ g/mol}}$$$$V_2 = 15.4 	ext{ L}$$

Quiz 4: Chemical Reactions

What is the molarity of methanol, CH₃OH (d = 0792 g/mL) , if 150.0 mL is dissolved in enough water to make 4.00 L of solution?

What is the molarity of a sucrose solution (C₁₂H₂₂O₁₁) if 110.0 g of a 92.0% pure solid is dissolved per 250.0 mL of water?

What mass of oxygen gas would be consumed by the complete combustion of 7.5 g of a mixture of propane (C₃H₈) and butane (C₄H₁₀) in the mole ratio of C₃H₈/C₄H₁₀ = 1.33?

What is the molarity of formaldehyde in a solution containing 0.25 g of formaldehyde (CH₂O) per mL?

What is the sum of the coefficients when the following is balanced with the smallest integer coefficients? CH₃OH → CO + H₂

How much Cl₂, in g, is required to produce 12.0 g CCl₄ according to the following reaction? CH₄ + 4 Cl₂ → CCl₄ + 4 HCl

You have 10.00 L of a 0.350 M KCl solution, but you need a solution that is 0.450 M. What volume of water, in L, would you evaporate from the solution?

What mass of water is produced in the metathesis reaction 75.2 g Zn(OH) ₂ with 43.4 g HCl?

What is the sum of the coefficients when the following equation is balanced with the smallest integer coefficients? H₂SO₃ + Al(OH) ₃ → Al₂(SO₃) ₃ + H₂O

The molarity of a solution that contains 14.7 g of H₂SO₄ in 200.0 mL solution is ________.

The chemical reaction occurring during the discharge of a lead storage battery can be represented by the equation: Pb(s) + PbO₂(s) + 2 H₂SO₄(aq) → 2 PbSO₄(s) + 2 H₂O(l) What mass of lead sulfate would result from the complete reaction of 41.4 g of lead?

If an aqueous solution containing 46 g of sodium carbonate per liter is mixed with an equal volume of 0.20 M aqueous hydrochloric acid, what would be the molarity of sodium chloride in the final solution, assuming volumes were additive?

Write the complete balanced equation for the complete combustion reaction expected to occur between C₃H₇OH and O₂.

Given the reaction: 2 KMnO₄ + 10 KI + 8 H₂SO₄ → 6 K₂SO₄ + 2 MnSO₄ + 5 I₂ + 8 H₂O How many moles of I2 are produced by reacting 28.0 g KMnO₄, 18.0 g KI, and 46.0 g H₂SO₄?

What mass of MgCl₂ in grams must be added to 250.0 mL of a 0.25 M MgCl₂ solution to produce a 0.40 M solution, assuming no change of volume upon addition?

To measure the volume of an irregularly shaped container filled with water, 1.00 mL of 2.00 M potassium chloride solution is added. After stirring, a 5.00 mL sample was found to contain 2.54 × 10^-2 mg of potassium ion. What is the volume of the container?

Quiz 4: Chemical Reactions

What is the molarity of methanol, CH3OH (d = 0792 g/mL) , if 150.0 mL is dissolved in enough water to make 4.00 L of solution?

What is the molarity of a sucrose solution (C12H22O11) if 110.0 g of a 92.0% pure solid is dissolved per 250.0 mL of water?

What mass of oxygen gas would be consumed by the complete combustion of 7.5 g of a mixture of propane (C3H8) and butane (C4H10) in the mole ratio of C3H8/C4H10 = 1.33?

What is the molarity of formaldehyde in a solution containing 0.25 g of formaldehyde (CH2O) per mL?

What is the sum of the coefficients when the following is balanced with the smallest integer coefficients? CH3OH → CO + H2

How much Cl2, in g, is required to produce 12.0 g CCl4 according to the following reaction? CH4 + 4 Cl2 → CCl4 + 4 HCl

You have 10.00 L of a 0.350 M KCl solution, but you need a solution that is 0.450 M. What volume of water, in L, would you evaporate from the solution?

What mass of water is produced in the metathesis reaction 75.2 g Zn(OH) 2 with 43.4 g HCl?

What is the sum of the coefficients when the following equation is balanced with the smallest integer coefficients? H2SO3 + Al(OH) 3 → Al2(SO3) 3 + H2O

The molarity of a solution that contains 14.7 g of H2SO4 in 200.0 mL solution is ________.

The chemical reaction occurring during the discharge of a lead storage battery can be represented by the equation: Pb(s) + PbO2(s) + 2 H2SO4(aq) → 2 PbSO4(s) + 2 H2O(l) What mass of lead sulfate would result from the complete reaction of 41.4 g of lead?

If an aqueous solution containing 46 g of sodium carbonate per liter is mixed with an equal volume of 0.20 M aqueous hydrochloric acid, what would be the molarity of sodium chloride in the final solution, assuming volumes were additive?

Write the complete balanced equation for the complete combustion reaction expected to occur between C3H7OH and O2.

Given the reaction: 2 KMnO4 + 10 KI + 8 H2SO4 → 6 K2SO4 + 2 MnSO4 + 5 I2 + 8 H2O How many moles of I2 are produced by reacting 28.0 g KMnO4, 18.0 g KI, and 46.0 g H2SO4?

What mass of MgCl2 in grams must be added to 250.0 mL of a 0.25 M MgCl2 solution to produce a 0.40 M solution, assuming no change of volume upon addition?

To measure the volume of an irregularly shaped container filled with water, 1.00 mL of 2.00 M potassium chloride solution is added. After stirring, a 5.00 mL sample was found to contain 2.54 × 10-2 mg of potassium ion. What is the volume of the container?

What is the molarity of methanol, CH₃OH (d = 0792 g/mL) , if 150.0 mL is dissolved in enough water to make 4.00 L of solution?

What is the molarity of a sucrose solution (C₁₂H₂₂O₁₁) if 110.0 g of a 92.0% pure solid is dissolved per 250.0 mL of water?

What mass of oxygen gas would be consumed by the complete combustion of 7.5 g of a mixture of propane (C₃H₈) and butane (C₄H₁₀) in the mole ratio of C₃H₈/C₄H₁₀ = 1.33?

What is the molarity of formaldehyde in a solution containing 0.25 g of formaldehyde (CH₂O) per mL?

What is the sum of the coefficients when the following is balanced with the smallest integer coefficients? CH₃OH → CO + H₂

How much Cl₂, in g, is required to produce 12.0 g CCl₄ according to the following reaction? CH₄ + 4 Cl₂ → CCl₄ + 4 HCl

What mass of water is produced in the metathesis reaction 75.2 g Zn(OH) ₂ with 43.4 g HCl?

What is the sum of the coefficients when the following equation is balanced with the smallest integer coefficients? H₂SO₃ + Al(OH) ₃ → Al₂(SO₃) ₃ + H₂O

The molarity of a solution that contains 14.7 g of H₂SO₄ in 200.0 mL solution is ________.

The chemical reaction occurring during the discharge of a lead storage battery can be represented by the equation: Pb(s) + PbO₂(s) + 2 H₂SO₄(aq) → 2 PbSO₄(s) + 2 H₂O(l) What mass of lead sulfate would result from the complete reaction of 41.4 g of lead?

Write the complete balanced equation for the complete combustion reaction expected to occur between C₃H₇OH and O₂.

Given the reaction: 2 KMnO₄ + 10 KI + 8 H₂SO₄ → 6 K₂SO₄ + 2 MnSO₄ + 5 I₂ + 8 H₂O How many moles of I2 are produced by reacting 28.0 g KMnO₄, 18.0 g KI, and 46.0 g H₂SO₄?

What mass of MgCl₂ in grams must be added to 250.0 mL of a 0.25 M MgCl₂ solution to produce a 0.40 M solution, assuming no change of volume upon addition?

To measure the volume of an irregularly shaped container filled with water, 1.00 mL of 2.00 M potassium chloride solution is added. After stirring, a 5.00 mL sample was found to contain 2.54 × 10^-2 mg of potassium ion. What is the volume of the container?