Question 1

Lithium and nitrogen react to produce lithium nitride: 6Li (s)+ N₂ (g)→ 2Li₃N (s) How many moles of lithium nitride are produced when 0.400 mol of lithium react in this fashion?

Accepted Answer

The balanced chemical equation is: 6Li (s)+ N₂ (g)→ 2Li₃N (s)From the balanced chemical equation, we can see that 6 moles of lithium react to produce 2 moles of lithium nitride. Therefore, 0.400 mol of lithium will react to produce 0.133 mol of lithium nitride.

Question 2

Magnesium burns in air with a dazzling brilliance to produce magnesium oxide: 2Mg (s)+ O₂ (g)→ 2MgO (s) How many moles of O₂ are consumed when 4.11 mol of magnesium burns?

Accepted Answer

According to the balanced equation, 2 moles of Mg react with 1 mole of O2. Therefore, 4.11 moles of Mg will react with 4.11/2 = 2.06 moles of O2.

Question 3

What is the empirical formula of a compound that is 52.1% C, 13.1% H, and 34.7% O by mass?

Accepted Answer

The answer of What is the empirical formula of a...

Question 4

A 3.92-g sample of magnesium nitrate, Mg(NO₃)₂, contains __________ mol of this compound.

Accepted Answer

The molar mass of Mg(NO3)2 is approximately 148.31 g/mol. To find the number of moles, divide the mass of the sample by the molar mass: 3.92 g / 148.31 g/mol ≈ 0.0264 mol.

Question 5

The combustion of ammonia in the presence of excess oxygen yields NO₂ and H₂O: 4 NH₃ (g)+ 7 O₂ (g)→ 4 NO₂ (g)+ 6 H₂O (g) The combustion of 57.6 g of ammonia consumes __________ g of oxygen.

Accepted Answer

The molar mass of NH₃ is 17.03 g/mol, so 57.6 g of NH₃ is 3.38 mol. According to the balanced equation, 4 mol of NH₃ requires 7 mol of O₂. Therefore, 3.38 mol of NH₃ requires 5.915 mol of O₂. The molar mass of O₂ is 32.00 g/mol, so 5.915 mol of O₂ is 189 g.

Question 6

The combustion of propane (C₃H₈)produces CO₂ and H₂O: C₃H₈ (g)+ 5 O₂ (g)→ 3CO₂ (g)+ 4 H₂O (g) The reaction of 5.5 mol of O₂ will produce __________ mol of H₂O.

Accepted Answer

According to balanced equation, 5 mol of O₂ produces 4 mol of H₂O, therefore 5.5 mol of O₂ produces: 4 mol H₂O/5 mol O₂ × 5.5 mol O₂ = 4.4 mol H₂O

Question 7

Calcium oxide reacts with water in a combination reaction to produce calcium hydroxide: CaO (s)+ H₂O (l)→ Ca(OH)₂ (s) A 4.00-g sample of CaO is reacted with 3.86 g of H₂O. How many grams of water remains after completion of reaction?

Accepted Answer

First, we need to determine the limiting reactant using stoichiometry.

4.00 g CaO x (1 mol CaO/56.077 g CaO) x (1 mol H2O/1 mol CaO) x (18.015 g H2O/1 mol H2O) = 1.286 g H2O

3.86 g H2SO4 x (1 mol H2SO4/98.079 g H2SO4) x (1 mol CaO/1 mol H2SO4) x (1 mol H2O/1 mol CaO) x (18.015 g H2O/1 mol H2O) = 0.722 g H2O

Since CaO is the limiting reactant (produces less product), only 1.286 g H2O can be produced. Therefore, the remaining water is:

3.86 g H2O - 1.286 g H2O = 2.57 g H2O

The answer is (C) 2.57.

Question 8

Calcium carbide (CaC₂)reacts with water to produce acetylene (C₂H₂): CaC₂ (s)+ 2 H₂O (g)→ Ca(OH)₂ (s)+ C₂H₂ (g) Production of 3.3 g of C₂H₂ requires consumption of __________ g of H₂O.

Accepted Answer

The molar mass of C2H2 is 26 g/mol, so 3.3 g corresponds to 0.127 mol. According to the balanced equation, 2 moles of H2O are needed for each mole of C2H2, so 0.254 mol of H2O is needed. The molar mass of H2O is 18 g/mol, so 0.254 mol corresponds to 4.6 g of H2O.

Question 9

Automotive air bags inflate when sodium azide decomposes explosively to its constituent elements: 2NaN₃ (s)→ 2Na (s)+ 3N₂ (g) How many grams of sodium azide are required to produce 30.5 g of nitrogen?

Accepted Answer

To find the grams of sodium azide required, first calculate the moles of nitrogen produced: 30.5 g N₂ / 28.02 g/mol = 1.088 moles N₂. From the balanced equation, 2 moles of NaN₃ produce 3 moles of N₂. Therefore, 1.088 moles N₂ require (2/3) * 1.088 = 0.725 moles NaN₃. The molar mass of NaN₃ is 65.01 g/mol, so 0.725 moles * 65.01 g/mol = 47.2 g NaN₃.

Question 10

Lead (II)carbonate decomposes to give lead (II)oxide and carbon dioxide: PbCO₃ (s)→ PbO (s)+ CO₂ (g) __________ grams of lead (II)oxide will be produced by the decomposition of 7.50 g of lead (II)carbonate?

Accepted Answer

The molar mass of PbCO₃ is approximately 267.21 g/mol, and the molar mass of PbO is approximately 223.20 g/mol. Using stoichiometry, 7.50 g of PbCO₃ will produce approximately 6.26 g of PbO.

Question 11

A certain alcohol contains only three elements, carbon, hydrogen, and oxygen. Combustion of a 30.00 gram sample of the alcohol produced 57.30 grams of CO₂ and 35.22 grams of H₂O. What is the empirical formula of the alcohol?

Accepted Answer

The answer of A certain alcohol contains only three elements,...

Question 12

Magnesium and nitrogen react in a combination reaction to produce magnesium nitride: 3 Mg + N₂ → Mg₃N₂ In a particular experiment, a 10.1-g sample of N₂ reacts completely. The mass of Mg consumed is __________ g.

Accepted Answer

The balanced chemical equation shows that 3 moles of Mg react with 1 mole of N2. The molar mass of Mg is 24.31 g/mol, and the molar mass of N2 is 28.01 g/mol. Therefore, 28.01 g of N2 react with 3 * 24.31 g = 72.93 g of Mg. Since 10.1 g of N2 reacts, the mass of Mg consumed is 10.1 g * 72.93 g / 28.01 g = 26.3 g.

Question 13

Lithium and nitrogen react in a combination reaction to produce lithium nitride: 6Li (s)+ N₂ (g)→ 2Li₃N (s) How many moles of lithium are needed to produce 0.20 mol of Li₃N when the reaction is carried out in the presence of excess nitrogen?

Accepted Answer

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

Question 14

Lithium and nitrogen react in a combination reaction to produce lithium nitride: 6Li (s)+ N₂ (g)→ 2Li₃N (s) In a particular experiment, 5.50-g samples of each reagent are reacted. The theoretical yield of lithium nitride is __________ g.

Accepted Answer

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

Question 15

Automotive air bags inflate when sodium azide decomposes explosively to its constituent elements: 2NaN₃ (s)→ 2Na (s)+ 3N₂ (g) How many moles of H₂ are produced by the decomposition of 3.55 mol of sodium azide?

Accepted Answer

According to the balanced equation, 2 moles of NaN₃ produce 3 moles of N₂. Therefore, 3.55 mol of NaN₃ will produce: 3.55 mol NaN₃ x (3 mol N₂/2 mol NaN₃) = 5.33 mol N₂ So, the answer is C) 5.33.

Question 16

Calcium oxide reacts with water in a combination reaction to produce calcium hydroxide: CaO (s)+ H₂O (l)→ Ca(OH)₂ (s) In a particular experiment, a 1.50-g sample of CaO is reacted with excess water and 1.48 g of Ca(OH)₂ is recovered. What is the percent yield in this experiment?

Accepted Answer

The first step is to calculate the theoretical yield of Ca(OH)2:

Molar mass of CaO = 56.08 g/mol
1.50 g of CaO is equal to 1.50 g / 56.08 g/mol = 0.02675 mol of CaO
The stoichiometry of the balanced equation shows that 1 mol of CaO produces 1 mol of Ca(OH)2
Therefore, the theoretical yield of Ca(OH)2 is also 0.02675 mol

Molar mass of Ca(OH)2 = 74.09 g/mol
0.02675 mol of Ca(OH)2 is equal to 1.98 g of Ca(OH)2
Therefore, the percent yield is:

(percent yield) = (actual yield ÷ theoretical yield) x 100%
(percent yield) = (1.48 g ÷ 1.98 g) x 100% = 74.8%

The correct answer is D, with a percent yield of 74.8%.

Question 17

Magnesium burns in air with a dazzling brilliance to produce magnesium oxide: 2Mg (s)+ O₂ (g)→ 2MgO (s) When 2.00 g of magnesium burns, the theoretical yield of magnesium oxide is __________ g.

Accepted Answer

The molar mass of Mg is 24.31 g/mol and MgO is 40.31 g/mol. Theoretical yield = (2.00 g Mg) * (1 mol Mg/24.31 g Mg) * (2 mol MgO/2 mol Mg) * (40.31 g MgO/1 mol MgO) = 3.32 g MgO.

Question 18

A 17.6-g sample of ammonium carbonate contains __________ mol of ammonium ions.

Accepted Answer

Ammonium carbonate ((NH4)2CO3) has a molar mass of approximately 96.09 g/mol. A 17.6-g sample contains 0.183 mol of ammonium carbonate, which has 2 ammonium ions per formula unit, resulting in 0.366 mol of ammonium ions.

Question 19

Lithium and nitrogen react to produce lithium nitride: 6Li (s)+ N₂ (g)→ 2Li₃N (s) How many moles of N₂ are needed to react with 0.710 mol of lithium?

Accepted Answer

According to the balanced equation, 6 moles of Li react with 1 mole of N₂. Therefore, 0.710 moles of Li would require 0.710/6 = 0.118 moles of N₂.

Question 20

If 2352 grams of FeS₂ is allowed to react with 1408 grams of O₂ according to the following equation, how many grams of Fe₂O₃ are produced? FeS₂ + O₂ → Fe₂O₃ + SO₂

Accepted Answer

The answer of If 2352 grams of FeS₂ is allowed...

Quiz 3: Stoichiometry: Calculations With Chemical Formulas and Equations

Lithium and nitrogen react to produce lithium nitride: 6Li (s) + N₂ (g) → 2Li₃N (s) How many moles of lithium nitride are produced when 0.400 mol of lithium react in this fashion?

Magnesium burns in air with a dazzling brilliance to produce magnesium oxide: 2Mg (s) + O₂ (g) → 2MgO (s) How many moles of O₂ are consumed when 4.11 mol of magnesium burns?

What is the empirical formula of a compound that is 52.1% C, 13.1% H, and 34.7% O by mass?

A 3.92-g sample of magnesium nitrate, Mg(NO₃) ₂, contains __________ mol of this compound.

The combustion of ammonia in the presence of excess oxygen yields NO₂ and H₂O: 4 NH₃ (g) + 7 O₂ (g) → 4 NO₂ (g) + 6 H₂O (g) The combustion of 57.6 g of ammonia consumes __________ g of oxygen.

The combustion of propane (C₃H₈) produces CO₂ and H₂O: C₃H₈ (g) + 5 O₂ (g) → 3CO₂ (g) + 4 H₂O (g) The reaction of 5.5 mol of O₂ will produce __________ mol of H₂O.

Calcium oxide reacts with water in a combination reaction to produce calcium hydroxide: CaO (s) + H₂O (l) → Ca(OH) ₂ (s) A 4.00-g sample of CaO is reacted with 3.86 g of H₂O. How many grams of water remains after completion of reaction?

Calcium carbide (CaC₂) reacts with water to produce acetylene (C₂H₂) : CaC₂ (s) + 2 H₂O (g) → Ca(OH) ₂ (s) + C₂H₂ (g) Production of 3.3 g of C₂H₂ requires consumption of __________ g of H₂O.

Automotive air bags inflate when sodium azide decomposes explosively to its constituent elements: 2NaN₃ (s) → 2Na (s) + 3N₂ (g) How many grams of sodium azide are required to produce 30.5 g of nitrogen?

Lead (II) carbonate decomposes to give lead (II) oxide and carbon dioxide: PbCO₃ (s) → PbO (s) + CO₂ (g) __________ grams of lead (II) oxide will be produced by the decomposition of 7.50 g of lead (II) carbonate?

A certain alcohol contains only three elements, carbon, hydrogen, and oxygen. Combustion of a 30.00 gram sample of the alcohol produced 57.30 grams of CO₂ and 35.22 grams of H₂O. What is the empirical formula of the alcohol?

Magnesium and nitrogen react in a combination reaction to produce magnesium nitride: 3 Mg + N₂ → Mg₃N₂ In a particular experiment, a 10.1-g sample of N₂ reacts completely. The mass of Mg consumed is __________ g.

Lithium and nitrogen react in a combination reaction to produce lithium nitride: 6Li (s) + N₂ (g) → 2Li₃N (s) How many moles of lithium are needed to produce 0.20 mol of Li₃N when the reaction is carried out in the presence of excess nitrogen?

Lithium and nitrogen react in a combination reaction to produce lithium nitride: 6Li (s) + N₂ (g) → 2Li₃N (s) In a particular experiment, 5.50-g samples of each reagent are reacted. The theoretical yield of lithium nitride is __________ g.

Automotive air bags inflate when sodium azide decomposes explosively to its constituent elements: 2NaN₃ (s) → 2Na (s) + 3N₂ (g) How many moles of H₂ are produced by the decomposition of 3.55 mol of sodium azide?

Calcium oxide reacts with water in a combination reaction to produce calcium hydroxide: CaO (s) + H₂O (l) → Ca(OH) ₂ (s) In a particular experiment, a 1.50-g sample of CaO is reacted with excess water and 1.48 g of Ca(OH) ₂ is recovered. What is the percent yield in this experiment?

Magnesium burns in air with a dazzling brilliance to produce magnesium oxide: 2Mg (s) + O₂ (g) → 2MgO (s) When 2.00 g of magnesium burns, the theoretical yield of magnesium oxide is __________ g.

A 17.6-g sample of ammonium carbonate contains __________ mol of ammonium ions.

Lithium and nitrogen react to produce lithium nitride: 6Li (s) + N₂ (g) → 2Li₃N (s) How many moles of N₂ are needed to react with 0.710 mol of lithium?

If 2352 grams of FeS₂ is allowed to react with 1408 grams of O₂ according to the following equation, how many grams of Fe₂O₃ are produced? FeS₂ + O₂ → Fe₂O₃ + SO₂

Quiz 3: Stoichiometry: Calculations With Chemical Formulas and Equations

Lithium and nitrogen react to produce lithium nitride: 6Li (s) + N2 (g) → 2Li3N (s) How many moles of lithium nitride are produced when 0.400 mol of lithium react in this fashion?

Magnesium burns in air with a dazzling brilliance to produce magnesium oxide: 2Mg (s) + O2 (g) → 2MgO (s) How many moles of O2 are consumed when 4.11 mol of magnesium burns?

What is the empirical formula of a compound that is 52.1% C, 13.1% H, and 34.7% O by mass?

A 3.92-g sample of magnesium nitrate, Mg(NO3) 2, contains __________ mol of this compound.

The combustion of ammonia in the presence of excess oxygen yields NO2 and H2O: 4 NH3 (g) + 7 O2 (g) → 4 NO2 (g) + 6 H2O (g) The combustion of 57.6 g of ammonia consumes __________ g of oxygen.

The combustion of propane (C3H8) produces CO2 and H2O: C3H8 (g) + 5 O2 (g) → 3CO2 (g) + 4 H2O (g) The reaction of 5.5 mol of O2 will produce __________ mol of H2O.

Calcium oxide reacts with water in a combination reaction to produce calcium hydroxide: CaO (s) + H2O (l) → Ca(OH) 2 (s) A 4.00-g sample of CaO is reacted with 3.86 g of H2O. How many grams of water remains after completion of reaction?

Calcium carbide (CaC2) reacts with water to produce acetylene (C2H2) : CaC2 (s) + 2 H2O (g) → Ca(OH) 2 (s) + C2H2 (g) Production of 3.3 g of C2H2 requires consumption of __________ g of H2O.

Automotive air bags inflate when sodium azide decomposes explosively to its constituent elements: 2NaN3 (s) → 2Na (s) + 3N2 (g) How many grams of sodium azide are required to produce 30.5 g of nitrogen?

Lead (II) carbonate decomposes to give lead (II) oxide and carbon dioxide: PbCO3 (s) → PbO (s) + CO2 (g) __________ grams of lead (II) oxide will be produced by the decomposition of 7.50 g of lead (II) carbonate?

A certain alcohol contains only three elements, carbon, hydrogen, and oxygen. Combustion of a 30.00 gram sample of the alcohol produced 57.30 grams of CO2 and 35.22 grams of H2O. What is the empirical formula of the alcohol?

Magnesium and nitrogen react in a combination reaction to produce magnesium nitride: 3 Mg + N2 → Mg3N2 In a particular experiment, a 10.1-g sample of N2 reacts completely. The mass of Mg consumed is __________ g.

Lithium and nitrogen react in a combination reaction to produce lithium nitride: 6Li (s) + N2 (g) → 2Li3N (s) How many moles of lithium are needed to produce 0.20 mol of Li3N when the reaction is carried out in the presence of excess nitrogen?

Lithium and nitrogen react in a combination reaction to produce lithium nitride: 6Li (s) + N2 (g) → 2Li3N (s) In a particular experiment, 5.50-g samples of each reagent are reacted. The theoretical yield of lithium nitride is __________ g.

Automotive air bags inflate when sodium azide decomposes explosively to its constituent elements: 2NaN3 (s) → 2Na (s) + 3N2 (g) How many moles of H2 are produced by the decomposition of 3.55 mol of sodium azide?

Calcium oxide reacts with water in a combination reaction to produce calcium hydroxide: CaO (s) + H2O (l) → Ca(OH) 2 (s) In a particular experiment, a 1.50-g sample of CaO is reacted with excess water and 1.48 g of Ca(OH) 2 is recovered. What is the percent yield in this experiment?

Magnesium burns in air with a dazzling brilliance to produce magnesium oxide: 2Mg (s) + O2 (g) → 2MgO (s) When 2.00 g of magnesium burns, the theoretical yield of magnesium oxide is __________ g.

A 17.6-g sample of ammonium carbonate contains __________ mol of ammonium ions.

Lithium and nitrogen react to produce lithium nitride: 6Li (s) + N2 (g) → 2Li3N (s) How many moles of N2 are needed to react with 0.710 mol of lithium?

If 2352 grams of FeS2 is allowed to react with 1408 grams of O2 according to the following equation, how many grams of Fe2O3 are produced? FeS2 + O2 → Fe2O3 + SO2

Lithium and nitrogen react to produce lithium nitride: 6Li (s) + N₂ (g) → 2Li₃N (s) How many moles of lithium nitride are produced when 0.400 mol of lithium react in this fashion?

Magnesium burns in air with a dazzling brilliance to produce magnesium oxide: 2Mg (s) + O₂ (g) → 2MgO (s) How many moles of O₂ are consumed when 4.11 mol of magnesium burns?

A 3.92-g sample of magnesium nitrate, Mg(NO₃) ₂, contains __________ mol of this compound.

The combustion of ammonia in the presence of excess oxygen yields NO₂ and H₂O: 4 NH₃ (g) + 7 O₂ (g) → 4 NO₂ (g) + 6 H₂O (g) The combustion of 57.6 g of ammonia consumes __________ g of oxygen.

The combustion of propane (C₃H₈) produces CO₂ and H₂O: C₃H₈ (g) + 5 O₂ (g) → 3CO₂ (g) + 4 H₂O (g) The reaction of 5.5 mol of O₂ will produce __________ mol of H₂O.

Calcium oxide reacts with water in a combination reaction to produce calcium hydroxide: CaO (s) + H₂O (l) → Ca(OH) ₂ (s) A 4.00-g sample of CaO is reacted with 3.86 g of H₂O. How many grams of water remains after completion of reaction?

Calcium carbide (CaC₂) reacts with water to produce acetylene (C₂H₂) : CaC₂ (s) + 2 H₂O (g) → Ca(OH) ₂ (s) + C₂H₂ (g) Production of 3.3 g of C₂H₂ requires consumption of __________ g of H₂O.

Automotive air bags inflate when sodium azide decomposes explosively to its constituent elements: 2NaN₃ (s) → 2Na (s) + 3N₂ (g) How many grams of sodium azide are required to produce 30.5 g of nitrogen?

Lead (II) carbonate decomposes to give lead (II) oxide and carbon dioxide: PbCO₃ (s) → PbO (s) + CO₂ (g) __________ grams of lead (II) oxide will be produced by the decomposition of 7.50 g of lead (II) carbonate?

A certain alcohol contains only three elements, carbon, hydrogen, and oxygen. Combustion of a 30.00 gram sample of the alcohol produced 57.30 grams of CO₂ and 35.22 grams of H₂O. What is the empirical formula of the alcohol?

Magnesium and nitrogen react in a combination reaction to produce magnesium nitride: 3 Mg + N₂ → Mg₃N₂ In a particular experiment, a 10.1-g sample of N₂ reacts completely. The mass of Mg consumed is __________ g.

Lithium and nitrogen react in a combination reaction to produce lithium nitride: 6Li (s) + N₂ (g) → 2Li₃N (s) How many moles of lithium are needed to produce 0.20 mol of Li₃N when the reaction is carried out in the presence of excess nitrogen?

Lithium and nitrogen react in a combination reaction to produce lithium nitride: 6Li (s) + N₂ (g) → 2Li₃N (s) In a particular experiment, 5.50-g samples of each reagent are reacted. The theoretical yield of lithium nitride is __________ g.

Automotive air bags inflate when sodium azide decomposes explosively to its constituent elements: 2NaN₃ (s) → 2Na (s) + 3N₂ (g) How many moles of H₂ are produced by the decomposition of 3.55 mol of sodium azide?

Calcium oxide reacts with water in a combination reaction to produce calcium hydroxide: CaO (s) + H₂O (l) → Ca(OH) ₂ (s) In a particular experiment, a 1.50-g sample of CaO is reacted with excess water and 1.48 g of Ca(OH) ₂ is recovered. What is the percent yield in this experiment?

Magnesium burns in air with a dazzling brilliance to produce magnesium oxide: 2Mg (s) + O₂ (g) → 2MgO (s) When 2.00 g of magnesium burns, the theoretical yield of magnesium oxide is __________ g.

Lithium and nitrogen react to produce lithium nitride: 6Li (s) + N₂ (g) → 2Li₃N (s) How many moles of N₂ are needed to react with 0.710 mol of lithium?

If 2352 grams of FeS₂ is allowed to react with 1408 grams of O₂ according to the following equation, how many grams of Fe₂O₃ are produced? FeS₂ + O₂ → Fe₂O₃ + SO₂