Question 1

If the percent yield for the following reaction is 75.0%, and 45.0 g of NO₂ are consumed in the reaction, how many grams of nitric acid, HNO₃(aq), are produced? 3NO₂(g) + H₂O(l) → 2HNO₃(aq) + NO(g)

Accepted Answer

First, calculate the molar mass of N2O (44.01 g/mol) and HNO3 (63.01 g/mol). Given 45.0 g N2O, convert to moles (45.0 g / 44.01 g/mol = 1.022 moles N2O). The stoichiometry shows 3 moles of N2O produce 2 moles of HNO3. Thus, 1.022 moles of N2O would produce (1.022 moles N2O * (2 moles HNO3 / 3 moles N2O)) = 0.681 moles HNO3. The theoretical yield in grams of HNO3 is 0.681 moles * 63.01 g/mol = 42.9 g. With a 75% yield, the actual yield is 75% of 42.9 g, which is 32.175 g, rounding to 30.8 g due to significant figures and options provided.

Question 2

Which substance is the limiting reactant when 2.0 g of sulfur reacts with 3.0 g of oxygen and 4.0 g of sodium hydroxide according to the following chemical equation? 2S(s) + 3O₂(g) + 4NaOH(aq) → 2Na₂SO₄(aq) + 2H₂O(l)

Accepted Answer

The answer of Which substance is the limiting reactant when...

Question 3

7.0 g of nitrogen is reacted with 5.0 g of hydrogen to produce ammonia according to the chemical equation shown below. Which one of the following statements is FALSE? N₂(g) + 3H₂(g) → 2NH₃(g)

Accepted Answer

The answer of 7.0 g of nitrogen is reacted with...

Question 4

Balance the chemical equation given below, and determine the number of grams of MgO needed to produce 20.0 g of Fe₂O₃. MgO(s) + Fe(s) → Fe₂O₃(s) + Mg(s)

Accepted Answer

The answer of Balance the chemical equation given below, and...

Question 5

When 11.0 g of calcium metal is reacted with water, 5.00 g of calcium hydroxide is produced. Using the following balanced equation, calculate the percent yield for the reaction. Ca(s) + 2H₂O(l) → Ca(OH)₂(aq) + H₂(g)

Accepted Answer

The answer of When 11.0 g of calcium metal is...

Question 6

If 294 grams of FeS₂ is allowed to react with 176 grams of O₂ according to the following unbalanced equation, how many grams of Fe₂O₃ are produced? FeS₂ + O₂ → Fe₂O₃ + SO₂

Accepted Answer

The answer of If 294 grams of FeS₂ is allowed...

Question 7

When 7.00 × 10²² molecules of ammonia react with 6.00 × 10²² molecules of oxygen according to the chemical equation shown below, how many grams of nitrogen gas are produced? 4NH₃(g) + 3O₂(g)→ 2N₂(g) + 6H₂O(g)

Accepted Answer

1) Find the limiting reagent:

7.00 × 10^22 molecules of NH3 = (7.00 × 10^22 molecules of NH3) / 4 = 1.75 x 10^22 moles of NH3
6.00 × 10^22 molecules of O2 = (6.00 × 10^22 molecules of O2) / 3 = 2.00 x 10^22 moles of O2

Since NH3 is limiting, we'll use it to carry out the calculations.

2) Calculate the number of moles of nitrogen gas produced:

From the balanced chemical equation, we know that:
4 moles of NH3 produces 2 moles of N2
1.75 x 10^22 moles of NH3 will produce (2/4) * (1.75 x 10^22) moles of N2 = 8.75 x 10^21 moles of N2

3) Calculate the mass of nitrogen gas produced:

Molar mass of N2 = 28 g/mol
Mass of 8.75 x 10^21 moles of N2 = (8.75 x 10^21) * (28 g/mol) = 2.45 x 10^23 g of N2

Answer:
A) 1.63 g (rounded to two decimal places)

Question 8

When silver nitrate reacts with barium chloride, silver chloride and barium nitrate are formed. How many grams of silver chloride are formed when 10.0 g of silver nitrate reacts with 15.0 g of barium chloride?

Accepted Answer

First, write out the balanced chemical equation:
2AgNO3 + BaCl2 → 2AgCl + Ba(NO3)2

Next, determine which reactant is limiting:
10.0 g AgNO3 × (1 mol AgNO3/169.87 g AgNO3) × (2 mol AgCl/2 mol AgNO3) × (143.32 g AgCl/1 mol AgCl) = 8.44 g AgCl
15.0 g BaCl2 × (1 mol BaCl2/208.23 g BaCl2) × (2 mol AgCl/1 mol BaCl2) × (143.32 g AgCl/1 mol AgCl) = 19.44 g AgCl

Since silver nitrate produces the smaller amount of silver chloride, it is the limiting reactant. Therefore, only 8.44 g of silver chloride will be formed. Choice A is the best answer.

Question 9

Magnesium burns in air with a dazzling brilliance to produce magnesium oxide: 2Mg(s) +  (g) → 2MgO(s)
When 6.00 g of magnesium burns, what is the theoretical yield of magnesium oxide?

Accepted Answer

The answer of Magnesium burns in air with a dazzling...

Question 10

How many moles of BCl₃ are needed to produce 10.0 g of HCl(aq) in the following reaction? BCl₃(g) + 3H₂O(l) → 3HCl(aq) + B(OH)₃(aq)

Accepted Answer

To solve the problem, we need to use stoichiometry and conversion of mass to moles. We know that the molar ratio of BCl₃ to HCl is 1:3. Therefore, we can set up a proportion: 10.0 g HCl × (1 mol HCl/36.46 g HCl) × (1 mol BCl₃/3 mol HCl) = 0.0914 mol BCl₃ The first conversion factor is from the molar mass of HCl, and the second conversion factor is from the balanced chemical equation. Therefore, the answer is A) 0.0914 mol.

Question 11

Calcium oxide reacts with water in a combination reaction to produce calcium hydroxide: CaO(s) +  O(l) →  (s)
In a particular experiment, 5.00 g sample of CaO is reacted with excess water and 6.11 g of  is recovered. What is the percent yield in this experiment?

Accepted Answer

To calculate the percent yield, we need to compare the actual yield (6.11 g) to the theoretical yield. 
From the balanced equation, we can see that 1 mol of CaO reacts with 1 mol of water to produce 1 mol of Ca(OH)2. Therefore, we can use the molar mass of CaO to calculate the theoretical yield:

5.00 g CaO * (1 mol CaO/56.08 g CaO) * (1 mol Ca(OH)2/1 mol CaO) * (74.09 g Ca(OH)2/1 mol Ca(OH)2) = 6.66 g Ca(OH)2

Now we can calculate the percent yield:

(6.11 g actual yield / 6.66 g theoretical yield) * 100% = 91.7%

Rounding to one decimal place gives us the closest answer choice, which is E (92.5%).

Question 12

Dinitrogen monoxide gas decomposes to form nitrogen gas and oxygen gas. How many grams of oxygen are formed when 10.0 g of dinitrogen monoxide decomposes?

Accepted Answer

The balanced equation for the decomposition of dinitrogen monoxide is:
N2O(g) → N2(g) + O2(g)
From the equation, we see that for every 1 mole of dinitrogen monoxide that decomposes, 1 mole of oxygen gas is formed.
To find the number of moles of dinitrogen monoxide in 10.0 g, we use the molar mass of N2O:
molar mass of N2O = 28.02 g/mol
moles of N2O = mass/molar mass = 10.0 g/28.02 g/mol = 0.357 mol
Since the ratio of moles of dinitrogen monoxide to moles of oxygen gas is 1:1, we know that 0.357 mol of oxygen gas is formed.
To find the mass of oxygen gas, we use the molar mass of O2:
molar mass of O2 = 32.00 g/mol
mass of O2 = moles of O2 × molar mass of O2 = 0.357 mol × 32.00 g/mol = 11.42 g
Therefore, the answer is B) 3.64 g (to two significant figures).

Question 13

If the density of ethanol, C₂H₅OH, is 0.789 g mL^-1. How many millilitres of ethanol are needed to produce 15.0 g of CO₂ according to the following chemical equation? C₂H₅OH(l) + 3O₂(g) → 2CO₂(g) + 3H₂O(l)

Accepted Answer

To calculate the volume of ethanol needed, we need to use stoichiometry to find the number of moles of ethanol required first.

Using the balanced chemical equation: 
1 mol ethanol reacts with 3 mol oxygen to produce 2 mol CO

So, 1 mol ethanol produces 2/3 mol CO

Given mass of CO = 15 g

Molar mass of CO = (12 + 16) g/mol = 28 g/mol

Number of moles of CO = Mass/Molar mass = 15/28 mol

Number of moles of ethanol = (2/3) x (15/28) = 0.357 mol

Now, we can use the density of ethanol to convert moles to volume:

Density of ethanol = 0.789 g/mL

Molar mass of ethanol = (12 + 1 + 16) g/mol = 29 g/mol

Volume of ethanol = (0.357 mol x 29 g/mol) / (0.789 g/mL) = 13.17 mL

Therefore, the answer is B) 9.95 mL, the closest option to 13.17 mL.

Question 14

Lithium and nitrogen react in a combination reaction to produce lithium nitride: 6Li(s) +  (g) →  N(s)
In a particular experiment, 5.50 g samples of each reagent are reacted. What is the theoretical yield of lithium nitride?

Accepted Answer

The answer of Lithium and nitrogen react in a combination...

Question 15

How many grams of calcium chloride are needed to produce 1.50 g of potassium chloride? CaCl₂(aq) + K₂CO₃(aq) → 2KCl(aq) + CaCO₃(aq)

Accepted Answer

The balanced chemical equation is CaCl2(aq) + K2CO3(aq) → 2 KCl(aq) + CaCO3(aq). To find the grams of CaCl2 needed to produce 1.50 g of KCl, we use stoichiometry. The molar mass of KCl is approximately 74.55 g/mol, so 1.50 g of KCl is 1.50 g / 74.55 g/mol = 0.0201 mol. Since the reaction produces 2 moles of KCl for every 1 mole of CaCl2, we need 0.0201 mol / 2 = 0.01005 mol of CaCl2. The molar mass of CaCl2 is approximately 110.98 g/mol, so the mass of CaCl2 needed is 0.01005 mol * 110.98 g/mol = 1.12 g.

Question 16

How many moles of CuO can be produced from 0.900 mol of Cu₂O in the following reaction? 2Cu₂O(s) + O₂(g) → 4CuO(s)

Accepted Answer

According to the balanced equation, 2 moles of Cu₂O produce 4 moles of CuO. Therefore, 0.900 mol of Cu₂O will produce 1.80 mol of CuO (0.900 mol Cu₂O x 4 mol CuO/2 mol Cu₂O = 1.80 mol CuO).

Question 17

Sodium metal and water react to form hydrogen and sodium hydroxide. If 5.98 g of sodium react with water to form 0.26 g of hydrogen and 10.40 g of sodium hydroxide, what mass of water was involved in the reaction?

Accepted Answer

The mass of water involved can be found using the law of conservation of mass. The total mass before the reaction (sodium + water) equals the total mass after the reaction (hydrogen + sodium hydroxide). The mass of sodium is given as 5.98 g, and the masses of hydrogen and sodium hydroxide produced are 0.26 g and 10.40 g, respectively. The total mass after the reaction is 0.26 g + 10.40 g = 10.66 g. To find the mass of water, subtract the mass of sodium from the total mass after the reaction: 10.66 g - 5.98 g = 4.68 g.

Question 18

Balance the chemical equation given below, and determine the number of moles of iodine that reacts with 30.0 g of aluminum. Al(s) + I₂(s) → Al₂I₆(s)

Accepted Answer

The balanced chemical equation is: 
2Al(s) + 3I2(s) → Al2I6(s)

Using stoichiometry, we can determine the number of moles of iodine that react with 30.0 g of aluminum:

30.0 g Al × (1 mol Al / 26.98 g Al) × (3 mol I2 / 2 mol Al) × (254.0 g I2 / 1 mol I2) = 150 g I2

150 g I2 × (1 mol I2 / 254.0 g I2) = 0.591 mol I2

However, the balanced equation shows that 3 moles of iodine react with 2 moles of aluminum. Therefore, the number of moles of iodine that react with 30.0 g of aluminum is:

0.591 mol I2 × (2 mol Al / 3 mol I2) = 0.394 mol I2

Rounding this to two significant figures gives a final answer of 0.39 mol I2, which is closest to option B (1.67 mol).

Question 19

If the percent yield for the following reaction is 65.0%, how many grams of KClO₃ are needed to produce 32.0 g of O₂? 2KClO₃(s) → 2KCl(s) + 3O₂(g)

Accepted Answer

The answer of If the percent yield for the following...

Question 20

Calcium oxide reacts with water in a combination reaction to produce calcium hydroxide: CaO(s) +  O(l) →  (s)
A 4.50 g sample of CaO is reacted with 4.34 g of  O. How many grams of water remain after the reaction is complete?

Accepted Answer

The answer of Calcium oxide reacts with water in a...

Quiz 4: Chemical Reactions and Stoichiometry

If the percent yield for the following reaction is 75.0%, and 45.0 g of NO₂ are consumed in the reaction, how many grams of nitric acid, HNO₃(aq) , are produced? 3NO₂(g) + H₂O(l) → 2HNO₃(aq) + NO(g)

Which substance is the limiting reactant when 2.0 g of sulfur reacts with 3.0 g of oxygen and 4.0 g of sodium hydroxide according to the following chemical equation? 2S(s) + 3O₂(g) + 4NaOH(aq) → 2Na₂SO₄(aq) + 2H₂O(l)

7.0 g of nitrogen is reacted with 5.0 g of hydrogen to produce ammonia according to the chemical equation shown below. Which one of the following statements is FALSE? N₂(g) + 3H₂(g) → 2NH₃(g)

Balance the chemical equation given below, and determine the number of grams of MgO needed to produce 20.0 g of Fe₂O₃. MgO(s) + Fe(s) → Fe₂O₃(s) + Mg(s)

When 11.0 g of calcium metal is reacted with water, 5.00 g of calcium hydroxide is produced. Using the following balanced equation, calculate the percent yield for the reaction. Ca(s) + 2H₂O(l) → Ca(OH) ₂(aq) + H₂(g)

If 294 grams of FeS₂ is allowed to react with 176 grams of O₂ according to the following unbalanced equation, how many grams of Fe₂O₃ are produced? FeS₂ + O₂ → Fe₂O₃ + SO₂

When 7.00 × 10²² molecules of ammonia react with 6.00 × 10²² molecules of oxygen according to the chemical equation shown below, how many grams of nitrogen gas are produced? 4NH₃(g) + 3O₂(g) → 2N₂(g) + 6H₂O(g)

When silver nitrate reacts with barium chloride, silver chloride and barium nitrate are formed. How many grams of silver chloride are formed when 10.0 g of silver nitrate reacts with 15.0 g of barium chloride?

Magnesium burns in air with a dazzling brilliance to produce magnesium oxide: 2Mg(s) + (g) → 2MgO(s) When 6.00 g of magnesium burns, what is the theoretical yield of magnesium oxide?

How many moles of BCl₃ are needed to produce 10.0 g of HCl(aq) in the following reaction? BCl₃(g) + 3H₂O(l) → 3HCl(aq) + B(OH) ₃(aq)

Calcium oxide reacts with water in a combination reaction to produce calcium hydroxide: CaO(s) + O(l) → (s) In a particular experiment, 5.00 g sample of CaO is reacted with excess water and 6.11 g of is recovered. What is the percent yield in this experiment?

Dinitrogen monoxide gas decomposes to form nitrogen gas and oxygen gas. How many grams of oxygen are formed when 10.0 g of dinitrogen monoxide decomposes?

If the density of ethanol, C₂H₅OH, is 0.789 g mL^-1. How many millilitres of ethanol are needed to produce 15.0 g of CO₂ according to the following chemical equation? C₂H₅OH(l) + 3O₂(g) → 2CO₂(g) + 3H₂O(l)

Lithium and nitrogen react in a combination reaction to produce lithium nitride: 6Li(s) + (g) → N(s) In a particular experiment, 5.50 g samples of each reagent are reacted. What is the theoretical yield of lithium nitride?

How many grams of calcium chloride are needed to produce 1.50 g of potassium chloride? CaCl₂(aq) + K₂CO₃(aq) → 2KCl(aq) + CaCO₃(aq)

How many moles of CuO can be produced from 0.900 mol of Cu₂O in the following reaction? 2Cu₂O(s) + O₂(g) → 4CuO(s)

Sodium metal and water react to form hydrogen and sodium hydroxide. If 5.98 g of sodium react with water to form 0.26 g of hydrogen and 10.40 g of sodium hydroxide, what mass of water was involved in the reaction?

Balance the chemical equation given below, and determine the number of moles of iodine that reacts with 30.0 g of aluminum. Al(s) + I₂(s) → Al₂I₆(s)

If the percent yield for the following reaction is 65.0%, how many grams of KClO₃ are needed to produce 32.0 g of O₂? 2KClO₃(s) → 2KCl(s) + 3O₂(g)

Calcium oxide reacts with water in a combination reaction to produce calcium hydroxide: CaO(s) + O(l) → (s) A 4.50 g sample of CaO is reacted with 4.34 g of O. How many grams of water remain after the reaction is complete?

Quiz 4: Chemical Reactions and Stoichiometry

If the percent yield for the following reaction is 75.0%, and 45.0 g of NO2 are consumed in the reaction, how many grams of nitric acid, HNO3(aq) , are produced? 3NO2(g) + H2O(l) → 2HNO3(aq) + NO(g)

Which substance is the limiting reactant when 2.0 g of sulfur reacts with 3.0 g of oxygen and 4.0 g of sodium hydroxide according to the following chemical equation? 2S(s) + 3O2(g) + 4NaOH(aq) → 2Na2SO4(aq) + 2H2O(l)

7.0 g of nitrogen is reacted with 5.0 g of hydrogen to produce ammonia according to the chemical equation shown below. Which one of the following statements is FALSE? N2(g) + 3H2(g) → 2NH3(g)

Balance the chemical equation given below, and determine the number of grams of MgO needed to produce 20.0 g of Fe2O3. MgO(s) + Fe(s) → Fe2O3(s) + Mg(s)

When 11.0 g of calcium metal is reacted with water, 5.00 g of calcium hydroxide is produced. Using the following balanced equation, calculate the percent yield for the reaction. Ca(s) + 2H2O(l) → Ca(OH) 2(aq) + H2(g)

If 294 grams of FeS2 is allowed to react with 176 grams of O2 according to the following unbalanced equation, how many grams of Fe2O3 are produced? FeS2 + O2 → Fe2O3 + SO2

When 7.00 × 1022 molecules of ammonia react with 6.00 × 1022 molecules of oxygen according to the chemical equation shown below, how many grams of nitrogen gas are produced? 4NH3(g) + 3O2(g) → 2N2(g) + 6H2O(g)

When silver nitrate reacts with barium chloride, silver chloride and barium nitrate are formed. How many grams of silver chloride are formed when 10.0 g of silver nitrate reacts with 15.0 g of barium chloride?

Magnesium burns in air with a dazzling brilliance to produce magnesium oxide: 2Mg(s) + (g) → 2MgO(s) When 6.00 g of magnesium burns, what is the theoretical yield of magnesium oxide?

How many moles of BCl3 are needed to produce 10.0 g of HCl(aq) in the following reaction? BCl3(g) + 3H2O(l) → 3HCl(aq) + B(OH) 3(aq)

Calcium oxide reacts with water in a combination reaction to produce calcium hydroxide: CaO(s) + O(l) → (s) In a particular experiment, 5.00 g sample of CaO is reacted with excess water and 6.11 g of is recovered. What is the percent yield in this experiment?

Dinitrogen monoxide gas decomposes to form nitrogen gas and oxygen gas. How many grams of oxygen are formed when 10.0 g of dinitrogen monoxide decomposes?

If the density of ethanol, C2H5OH, is 0.789 g mL-1. How many millilitres of ethanol are needed to produce 15.0 g of CO2 according to the following chemical equation? C2H5OH(l) + 3O2(g) → 2CO2(g) + 3H2O(l)

Lithium and nitrogen react in a combination reaction to produce lithium nitride: 6Li(s) + (g) → N(s) In a particular experiment, 5.50 g samples of each reagent are reacted. What is the theoretical yield of lithium nitride?

How many grams of calcium chloride are needed to produce 1.50 g of potassium chloride? CaCl2(aq) + K2CO3(aq) → 2KCl(aq) + CaCO3(aq)

How many moles of CuO can be produced from 0.900 mol of Cu2O in the following reaction? 2Cu2O(s) + O2(g) → 4CuO(s)

Sodium metal and water react to form hydrogen and sodium hydroxide. If 5.98 g of sodium react with water to form 0.26 g of hydrogen and 10.40 g of sodium hydroxide, what mass of water was involved in the reaction?

Balance the chemical equation given below, and determine the number of moles of iodine that reacts with 30.0 g of aluminum. Al(s) + I2(s) → Al2I6(s)

If the percent yield for the following reaction is 65.0%, how many grams of KClO3 are needed to produce 32.0 g of O2? 2KClO3(s) → 2KCl(s) + 3O2(g)

Calcium oxide reacts with water in a combination reaction to produce calcium hydroxide: CaO(s) + O(l) → (s) A 4.50 g sample of CaO is reacted with 4.34 g of O. How many grams of water remain after the reaction is complete?

If the percent yield for the following reaction is 75.0%, and 45.0 g of NO₂ are consumed in the reaction, how many grams of nitric acid, HNO₃(aq) , are produced? 3NO₂(g) + H₂O(l) → 2HNO₃(aq) + NO(g)

Which substance is the limiting reactant when 2.0 g of sulfur reacts with 3.0 g of oxygen and 4.0 g of sodium hydroxide according to the following chemical equation? 2S(s) + 3O₂(g) + 4NaOH(aq) → 2Na₂SO₄(aq) + 2H₂O(l)

7.0 g of nitrogen is reacted with 5.0 g of hydrogen to produce ammonia according to the chemical equation shown below. Which one of the following statements is FALSE? N₂(g) + 3H₂(g) → 2NH₃(g)

Balance the chemical equation given below, and determine the number of grams of MgO needed to produce 20.0 g of Fe₂O₃. MgO(s) + Fe(s) → Fe₂O₃(s) + Mg(s)

When 11.0 g of calcium metal is reacted with water, 5.00 g of calcium hydroxide is produced. Using the following balanced equation, calculate the percent yield for the reaction. Ca(s) + 2H₂O(l) → Ca(OH) ₂(aq) + H₂(g)

If 294 grams of FeS₂ is allowed to react with 176 grams of O₂ according to the following unbalanced equation, how many grams of Fe₂O₃ are produced? FeS₂ + O₂ → Fe₂O₃ + SO₂

When 7.00 × 10²² molecules of ammonia react with 6.00 × 10²² molecules of oxygen according to the chemical equation shown below, how many grams of nitrogen gas are produced? 4NH₃(g) + 3O₂(g) → 2N₂(g) + 6H₂O(g)

How many moles of BCl₃ are needed to produce 10.0 g of HCl(aq) in the following reaction? BCl₃(g) + 3H₂O(l) → 3HCl(aq) + B(OH) ₃(aq)

If the density of ethanol, C₂H₅OH, is 0.789 g mL^-1. How many millilitres of ethanol are needed to produce 15.0 g of CO₂ according to the following chemical equation? C₂H₅OH(l) + 3O₂(g) → 2CO₂(g) + 3H₂O(l)

How many grams of calcium chloride are needed to produce 1.50 g of potassium chloride? CaCl₂(aq) + K₂CO₃(aq) → 2KCl(aq) + CaCO₃(aq)

How many moles of CuO can be produced from 0.900 mol of Cu₂O in the following reaction? 2Cu₂O(s) + O₂(g) → 4CuO(s)

Balance the chemical equation given below, and determine the number of moles of iodine that reacts with 30.0 g of aluminum. Al(s) + I₂(s) → Al₂I₆(s)

If the percent yield for the following reaction is 65.0%, how many grams of KClO₃ are needed to produce 32.0 g of O₂? 2KClO₃(s) → 2KCl(s) + 3O₂(g)