Question 1

"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 reaction between calcium ions (Ca^2+) and sodium carbonate (Na2CO3) to form calcium carbonate (CaCO3) is a 1:1 molar ratio. First, calculate the moles of Ca^2+ in 750 L of solution: $750 \, \text{L} \times \frac{43 \, \text{mg Ca}^{2+}}{1 \, \text{L}} \times \frac{1 \, \text{g}}{1000 \, \text{mg}} \times \frac{1 \, \text{mol Ca}^{2+}}{40.08 \, \text{g}} = 0.804 \, \text{mol Ca}^{2+}$. Since the reaction is 1:1, 0.804 mol of Na2CO3 is needed. The molar mass of Na2CO3 is approximately 106 g/mol, so $0.804 \, \text{mol} \times 106 \, \text{g/mol} = 85.224 \, \text{g}$. Therefore, 85 g of sodium carbonate is required.

Question 2

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 correct answer is A because the molarity of sodium chloride in the final solution is 0.10 M. This is because the sodium carbonate and hydrochloric acid react in a 1:2 ratio, so the final solution will contain half of the original amount of sodium carbonate and all of the original amount of hydrochloric acid. The molarity of sodium chloride in the final solution will therefore be 0.10 M.

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

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

Accepted Answer

The balanced equation for the combustion of C₃H₇OH with O₂ is: 2 C₃H₇OH + 9 O₂ → 6 CO₂ + 8 H₂O This equation is balanced because there are equal numbers of atoms of each element on both the reactant and product sides of the equation. Option D is the only choice that matches this balanced equation.

Question 5

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

Accepted Answer

To find the molarity, we need to know the amount of formaldehyde in moles and the volume of the solution in liters.

First, we need to convert the given mass of formaldehyde to moles:

0.25 g CH2O × (1 mol CH2O/30.03 g CH2O) = 0.00833 mol CH2O

Next, we need to assume that the solution has a density of 1 g/mL, which means that 1 mL of the solution has a mass of 1 g. Therefore, the volume of the solution in liters is also 0.25 L.

Finally, we can calculate the molarity:

Molarity = moles of solute/volume of solution
Molarity = 0.00833 mol CH2O/0.25 L = 0.0332 M

Rounding to two significant figures, we get a molarity of 0.033 M or 8.3 M. Therefore, the best choice is C, 8.3 M.

Question 6

What is the sum of the coefficients when the following is balanced with the smallest integer coefficients? H₂(g)+ O₂(g)→ H₂O(l)

Accepted Answer

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

Question 7

The chemical reaction occurring during the discharge of a lead storage battery can be represented by the equation: 
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 8

What is the molarity of methanol, 
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, 
If...

Question 9

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 
What is the volume of blood in the elephant?

Accepted Answer

The answer of Our task is to measure the volume...

Question 10

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

Accepted Answer

The balanced chemical equation is 2CH₃OH → 2CO + H2₂ + O2. The sum of the coefficients is 2 + 2 + 1 + 1 = 6, but since the question seems to have a typo and doesn't accurately reflect a real chemical reaction, the closest correct choice given the options would be 4, assuming a misinterpretation or simplification of the intended chemical equation.

Question 11

What is the sum of the coefficients when the following is balanced with the smallest integer coefficients? Al(s)+ HCl(aq)→ AlCl₃(aq)+ H₂(g)

Accepted Answer

The balanced chemical equation is 2Al(s) + 6HCl(aq) → 2AlCl3(aq) + 3H2(g), with coefficients summing to 2 + 6 + 2 + 3 = 13.

Question 12

What is the sum of the coefficients when the following is balanced with the smallest integer coefficients? C₂H₆ + O₂ → CO₂ + H₂O

Accepted Answer

To balance the equation, we need to add coefficients to each molecule. We start by balancing the atoms involved in the reaction. For example, we have 1 Carbon, 3 Oxygen, 3 Sulfur, and 14 Hydrogen on the left, and 1 Carbon, 3 Oxygen, 3 Sulfur, and 14 Hydrogen on the right. The smallest integer coefficients that balance the equation are: 1 C₂H₆ + 1 O₂ → 1 CO₂ + 16 H₂O The sum of the coefficients is 1+1+1+16=19, so the answer is C.

Question 13

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 14

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

Use the formula: M1V1 = M2V2 Rearrange to solve for V2, the volume of the 0.40 M solution to be produced: V2 = M1V1/M2 = (0.25 M)(250.0 mL)/(0.40 M) = 156.25 mL This is the volume of the final solution. To find the mass of MgCl₂ needed, use the formula: mass = moles x molar mass First, calculate the number of moles needed in the final solution: moles = M x L = (0.40 M)(156.25 mL/1000 mL) = 0.0625 moles Next, calculate the mass of MgCl₂ needed: mass = moles x molar mass = (0.0625 moles)(95.211 g/mol) = 5.95 g Therefore, the closest answer choice is D) 3.6 g.

Question 15

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 balanced chemical equation is: 2 H2SO4 + Al(OH)3 → Al2(SO4)3 + 3 H2O. Summing the coefficients gives 2 + 1 + 1 + 3 = 7. However, due to the formatting error in the question, the correct interpretation and balancing of the equation cannot be directly applied. Assuming a standard reaction between sulfuric acid and aluminum hydroxide, the sum of coefficients in a correctly balanced equation would typically be 7, not matching any of the provided options. Given the options and the potential misunderstanding from the formatting, there's no accurate way to determine the correct sum based on standard chemical reaction balancing. The response assumes a mistake in interpreting the provided equation due to formatting issues.

Question 16

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 17

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 18

How much Cl₂,in g,is required to produce 12.0 g CCl₄ according to the following reaction?

Accepted Answer

The answer of How much Cl₂,in g,is required to produce...

Question 19

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

Accepted Answer

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

Question 20

What is the sum of the coefficients when the following is balanced with the smallest integer coefficients? PCl₃(l)+ Cl₂(g)+ P₄O₁₀(s)→ POCl₃(l)

Accepted Answer

The balanced chemical equation is: PCl5(l) + Cl2(g) + P4O10(s) → 6POCl3(l). The sum of the coefficients is 1 + 1 + 1 + 6 = 9. However, the question seems to have a typo in the options provided, as none of the options match the calculated sum of 9. Based on the closest available option and assuming a potential misinterpretation or typo, the correct choice intended might be E) 23, considering a different interpretation of the question or a mistake in the calculation or options provided.

Quiz 4: Chemical Reactions

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?

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?

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

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? H₂(g) + O₂(g) → H₂O(l)

The chemical reaction occurring during the discharge of a lead storage battery can be represented by the equation: What mass of lead sulfate would result from the complete reaction of 41.4 g of lead?

What is the molarity of methanol, If 150.0 mL is dissolved in enough water to make 4.00 L of solution?

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

What is the sum of the coefficients when the following is balanced with the smallest integer coefficients? Al(s) + HCl(aq) → AlCl₃(aq) + H₂(g)

What is the sum of the coefficients when the following is balanced with the smallest integer coefficients? C₂H₆ + O₂ → CO₂ + H₂O

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 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?

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

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

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

How much Cl₂,in g,is required to produce 12.0 g CCl₄ according to the following reaction?

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

What is the sum of the coefficients when the following is balanced with the smallest integer coefficients? PCl₃(l) + Cl₂(g) + P₄O₁₀(s) → POCl₃(l)

Quiz 4: Chemical Reactions

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?

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?

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

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? H2(g) + O2(g) → H2O(l)

The chemical reaction occurring during the discharge of a lead storage battery can be represented by the equation: What mass of lead sulfate would result from the complete reaction of 41.4 g of lead?

What is the molarity of methanol, If 150.0 mL is dissolved in enough water to make 4.00 L of solution?

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

What is the sum of the coefficients when the following is balanced with the smallest integer coefficients? Al(s) + HCl(aq) → AlCl3(aq) + H2(g)

What is the sum of the coefficients when the following is balanced with the smallest integer coefficients? C2H6 + O2 → CO2 + H2O

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 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?

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

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

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

How much Cl2,in g,is required to produce 12.0 g CCl4 according to the following reaction?

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

What is the sum of the coefficients when the following is balanced with the smallest integer coefficients? PCl3(l) + Cl2(g) + P4O10(s) → POCl3(l)

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?

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

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? H₂(g) + O₂(g) → H₂O(l)

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

What is the sum of the coefficients when the following is balanced with the smallest integer coefficients? Al(s) + HCl(aq) → AlCl₃(aq) + H₂(g)

What is the sum of the coefficients when the following is balanced with the smallest integer coefficients? C₂H₆ + O₂ → CO₂ + H₂O

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?

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

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

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

How much Cl₂,in g,is required to produce 12.0 g CCl₄ according to the following reaction?

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

What is the sum of the coefficients when the following is balanced with the smallest integer coefficients? PCl₃(l) + Cl₂(g) + P₄O₁₀(s) → POCl₃(l)