Question 1

Given that 4NH3(g)+ 5O2(g)→ 4NO(g)+ 6H2O(g), if 8.2 moles of NH3 react with sufficient oxygen, how many moles of water should form?

Accepted Answer

A) 6.0 moles 
B) 4.0 moles 
C) 5.0 moles 
D) 12 moles 
E) 8.2 moles 
A) 6.0 moles 
B) 4.0 moles 
C) 5.0 moles 
D) 12 moles 
E) 8.2 moles

Question 2

When a 0.525 g piece of zinc is placed in a solution of copper(II)sulfate, copper metal and zinc sulfate are formed. Balance the equation for the reaction, and determine the mass of copper(II)sulfate that would react with this quantity of zinc. ___ Zn(s)+ ___CuSO4(aq)→ ___ZnSO4(aq)+ ___Cu(s)(unbalanced)

Accepted Answer

A) 65.4 g 
B) 0.641 g 
C) 1.28 g 
D) 2.56 g 
E) 159 g 
A) 65.4 g 
B) 0.641 g 
C) 1.28 g 
D) 2.56 g 
E) 159 g

Question 3

Ammonia is usually made by the following reaction: N2(g)+ 3H2(g)→ 2NH3(g)What is the maximum amount of ammonia that can be formed if 30 molecules of nitrogen are mixed with 100 molecules of hydrogen?

Accepted Answer

A) 20 molecules 
B) 30 molecules 
C) 40 molecules 
D) 60 molecules 
E) 70 molecules 
A) 20 molecules 
B) 30 molecules 
C) 40 molecules 
D) 60 molecules 
E) 70 molecules

Question 4

The figure shows a molecular-level diagram of reactant molecules for the reaction: 2C2H2(g)+ 5O2(g)→ 4CO2(g)+ 2H2O(g)   List the number and formulas of the molecules that should be present after the reaction takes place.

Accepted Answer

A) 4CO2 + 2H2O 
B) 4CO2 + 2H2O + 2C2H2 
C) 4CO2 + 2H2O + 2C2H2 + 5O2 
D) 6CO2 + 3H2O + 3O2 
E) 8CO2 + 4H2O + 2C2H2 
A) 4CO2 + 2H2O 
B) 4CO2 + 2H2O + 2C2H2 
C) 4CO2 + 2H2O + 2C2H2 + 5O2 
D) 6CO2 + 3H2O + 3O2 
E) 8CO2 + 4H2O + 2C2H2

Question 5

When mercury(II)oxide, a red crystalline solid, is heated, it decomposes to form liquid mercury and oxygen gas, according to the following equation: ___HgO(s)→ ___Hg(l)+ ___O2(g)(unbalanced)Balance the equation and determine the mass of mercury that should be formed when 15.6 g of HgO is heated.

Accepted Answer

A) 28.9 g 
B) 7.22 g 
C) 14.4 g 
D) 16.9 g 
E) 13.2 g 
A) 28.9 g 
B) 7.22 g 
C) 14.4 g 
D) 16.9 g 
E) 13.2 g

Question 6

Phosphine, PH3, a reactive and poisonous compound, reacts with oxygen as follows: 4PH3(g)+ 8O2(g)→ P4O10(s)+ 6H2O(g)If 15.0 g of phosphine reacts with sufficient oxygen, how many grams of P4O10 will be formed?

Accepted Answer

A) 125 g 
B) 31.3 g 
C) 5.00 x 102 g 
D) 18.9 g 
E) 75.7 g 
A) 125 g 
B) 31.3 g 
C) 5.00 x 102 g 
D) 18.9 g 
E) 75.7 g

Question 7

A 2.50 g sample of pitted prunes was burned in a bomb calorimeter containing 2110 g of water. The temperature of the water increased from 22.50°C to 25.76°C. How much heat, in joules, did the prune sample release when it burned? [Cwater = 4.184 J/(g°C)]

Accepted Answer

A) 1.99 x 105 J 
B) 2.27 x 105 J 
C) 2.88 x 104 J 
D) 2.35 x 102 J 
E) 2.69 x 102 J 
A) 1.99 x 105 J 
B) 2.27 x 105 J 
C) 2.88 x 104 J 
D) 2.35 x 102 J 
E) 2.69 x 102 J

Question 8

When mixed, solutions of silver nitrate, AgNO3, and sodium phosphate, Na3PO4, will form a precipitate of silver phosphate, Ag3PO4. The balanced equation is 3AgNO3(aq)+ Na3PO4(aq)→ Ag3PO4(s)+ 3NaNO3(aq)Which of the following statements regarding this reaction is incorrect?

Accepted Answer

A) 6 moles of AgNO3 will react with 2 moles of Na3PO4. 
B) 9 moles of AgNO3 should react to form 2 moles of Ag3PO4, given sufficient Na3PO4. 
C) 1.5 moles of NaNO3 should form when 0.5 mole of Na3PO4 reacts with sufficient AgNO3. 
D) 3 moles of Ag3PO4 should form when 3 moles of Na3PO4 react with sufficient AgNO3. 
E) 2 moles of Na3PO4 will react with 6 moles of AgNO3. 
A) 6 moles of AgNO3 will react with 2 moles of Na3PO4. 
B) 9 moles of AgNO3 should react to form 2 moles of Ag3PO4, given sufficient Na3PO4. 
C) 1.5 moles of NaNO3 should form when 0.5 mole of Na3PO4 reacts with sufficient AgNO3. 
D) 3 moles of Ag3PO4 should form when 3 moles of Na3PO4 react with sufficient AgNO3. 
E) 2 moles of Na3PO4 will react with 6 moles of AgNO3.

Question 9

The q value for the following reaction is 178.0 kJ for every mole of CaCO3 that reacts: CaCO3(s)→ CaO(s)+ CO2(g)How much heat would be required to decompose 4.00 mol CaCO3(s), and is the reaction endothermic or exothermic?

Accepted Answer

A) 712 kJ; exothermic 
B) 712 kJ; endothermic 
C) 178 kJ; exothermic 
D) 44.5 kJ; endothermic 
E) 44.5 kJ; exothermic 
A) 712 kJ; exothermic 
B) 712 kJ; endothermic 
C) 178 kJ; exothermic 
D) 44.5 kJ; endothermic 
E) 44.5 kJ; exothermic

Question 10

When potassium metal is exposed to air, it forms a coating of potassium oxide, according to the following equation: 4K(s)+ O2(g)→ 2K2O(s)If a piece of potassium gains 0.354 g, assuming this gain can be attributed to the above reaction with oxygen, what mass of oxygen reacted with the potassium? Report your answer with the correct number of significant figures and correct units.

Accepted Answer

To determine the mass of oxygen that rea

Question 11

Consider the following specific heats of metals.   If the same amount of heat is added to 25.0 g of each of these metals, all at the same initial temperature, which metal will have the highest final temperature?

Accepted Answer

A) copper 
B) calcium 
C) aluminum 
D) iron 
E) lead 
A) copper 
B) calcium 
C) aluminum 
D) iron 
E) lead

Question 12

Consider the reaction N2(g)+ O2(g)→ 2NO(g). The molecular image represents a mixture of N2(g)and O2(g)just before reaction occurs. What is the limiting reactant, and how much of the excess reactant remains after the reaction is complete? The image contains 2 N2 molecules and 4 O2 molecules.

Accepted Answer

A) N2(g), 1 O2(g) 
B) N2(g), 2 O2(g) 
C) N2(g), 3 O2(g) 
D) O2(g), 1 N2(g) 
E) N2(g), 0 O2(g) 
A) N2(g), 1 O2(g) 
B) N2(g), 2 O2(g) 
C) N2(g), 3 O2(g) 
D) O2(g), 1 N2(g) 
E) N2(g), 0 O2(g)

Question 13

When 5.0 g CaCl2 is dissolved in water, how many moles of ions are in solution?

Accepted Answer

A) 0.135 mole 
B) 0.045 mole 
C) 5.0 moles 
D) 15.0 moles 
E) 1660 moles 
A) 0.135 mole 
B) 0.045 mole 
C) 5.0 moles 
D) 15.0 moles 
E) 1660 moles

Question 14

Given that 4NH3(g)+ 5O2(g)→ 4NO(g)+ 6H2O(g), if 4.5 moles of NH3 react with sufficient oxygen, how many moles of H2O should form?

Accepted Answer

A) 4.0 
B) 4.5 
C) 6.0 
D) 6.8 
E) 5.5 
A) 4.0 
B) 4.5 
C) 6.0 
D) 6.8 
E) 5.5

Question 15

Aluminum metal reacts with sulfuric acid according to the following equation: 2Al(s)+ 3H2SO4(aq)→ Al2(SO4)3(s)+ 3H2(g)If 10.0 g of aluminum reacts with excess sulfuric acid, and 54.2 g of Al2(SO4)3 are collected, what is the percent yield of Al2(SO4)3?

Accepted Answer

A) 63.4% 
B) 85.5% 
C) 117% 
D) 47.1% 
E) not enough information given 
A) 63.4% 
B) 85.5% 
C) 117% 
D) 47.1% 
E) not enough information given

Question 16

Consider the following reaction: Cr2O3(s)+ 3CCl4(l)→ 2CrCl3(s)+ 3COCl2(g)green colorless purple colorless solid liquid solid gas When the green solid is mixed with the colorless liquid, the mixture starts to bubble and fume. When all action has stopped, a dry purple solid containing solid green specks remains. Which substance is the limiting reactant?

Accepted Answer

A) Cr2O3 
B) CCl4 
C) CrCl3 
D) COCl2 
E) there is no limiting reactant 
A) Cr2O3 
B) CCl4 
C) CrCl3 
D) COCl2 
E) there is no limiting reactant

Question 17

Which of the following processes is endothermic?

Accepted Answer

A) burning gasoline in an internal combustion engine 
B) evaporation of perspiration on your skin 
C) burning wood in a fireplace 
D) condensing steam on a mirror 
E) hot coffee cooling down as it sits on the table 
A) burning gasoline in an internal combustion engine 
B) evaporation of perspiration on your skin 
C) burning wood in a fireplace 
D) condensing steam on a mirror 
E) hot coffee cooling down as it sits on the table

Question 18

Phosphorus trichloride can be made by the following reaction: P4(s)+ 6Cl2(g)→ 4PCl3(l)What is the maximum amount of phosphorus trichloride that can be formed if 15 molecules of P4 are mixed with 42 molecules of chlorine?

Accepted Answer

A) 4 molecules 
B) 12 molecules 
C) 24 molecules 
D) 28 molecules 
E) 57 molecules 
A) 4 molecules 
B) 12 molecules 
C) 24 molecules 
D) 28 molecules 
E) 57 molecules

Question 19

Which of the following is the best (simplest)balanced equation to represent the chemical reaction shown in the figure on any scale?

Accepted Answer

A) 12N + 12H → 12NH 
B) 6N2 + 6H2 → 4NH3 
C) 6N2 + 6H2 → 4NH3 + 4N2 
D) 12N + 12H → 4NH3 + 8N 
E) N2 + 3H2 → 2NH3 
A) 12N + 12H → 12NH 
B) 6N2 + 6H2 → 4NH3 
C) 6N2 + 6H2 → 4NH3 + 4N2 
D) 12N + 12H → 4NH3 + 8N 
E) N2 + 3H2 → 2NH3

Question 20

An energy input of 227 kJ is required to form acetylene from its elements. Convert this energy to units of calories.

Accepted Answer

A) 9.50 x 102 cal 
B) 9.50 x 105 cal 
C) 0.227 cal 
D) 54.3 cal 
E) 5.43 x 104 cal 
A) 9.50 x 102 cal 
B) 9.50 x 105 cal 
C) 0.227 cal 
D) 54.3 cal 
E) 5.43 x 104 cal

Given that 4NH₃(g)+ 5O₂(g)→ 4NO(g)+ 6H₂O(g), if 8.2 moles of NH₃ react with sufficient oxygen, how many moles of water should form?

Ammonia is usually made by the following reaction: N₂(g)+ 3H₂(g)→ 2NH₃(g)What is the maximum amount of ammonia that can be formed if 30 molecules of nitrogen are mixed with 100 molecules of hydrogen?

The figure shows a molecular-level diagram of reactant molecules for the reaction: 2C₂H₂(g)+ 5O₂(g)→ 4CO₂(g)+ 2H₂O(g) List the number and formulas of the molecules that should be present after the reaction takes place.

When mercury(II)oxide, a red crystalline solid, is heated, it decomposes to form liquid mercury and oxygen gas, according to the following equation: _HgO(s)→ _Hg(l)+ ___O₂(g)(unbalanced)Balance the equation and determine the mass of mercury that should be formed when 15.6 g of HgO is heated.

Phosphine, PH₃, a reactive and poisonous compound, reacts with oxygen as follows: 4PH₃(g)+ 8O₂(g)→ P₄O₁₀(s)+ 6H₂O(g)If 15.0 g of phosphine reacts with sufficient oxygen, how many grams of P₄O₁₀ will be formed?

A 2.50 g sample of pitted prunes was burned in a bomb calorimeter containing 2110 g of water. The temperature of the water increased from 22.50°C to 25.76°C. How much heat, in joules, did the prune sample release when it burned? [C_water = 4.184 J/(g°C)]

When mixed, solutions of silver nitrate, AgNO₃, and sodium phosphate, Na₃PO₄, will form a precipitate of silver phosphate, Ag₃PO₄. The balanced equation is 3AgNO₃(aq)+ Na₃PO₄(aq)→ Ag₃PO₄(s)+ 3NaNO₃(aq)Which of the following statements regarding this reaction is incorrect?

The q value for the following reaction is 178.0 kJ for every mole of CaCO₃ that reacts: CaCO₃(s)→ CaO(s)+ CO₂(g)How much heat would be required to decompose 4.00 mol CaCO₃(s), and is the reaction endothermic or exothermic?

Consider the following specific heats of metals. If the same amount of heat is added to 25.0 g of each of these metals, all at the same initial temperature, which metal will have the highest final temperature?

When 5.0 g CaCl₂ is dissolved in water, how many moles of ions are in solution?

Given that 4NH₃(g)+ 5O₂(g)→ 4NO(g)+ 6H₂O(g), if 4.5 moles of NH₃ react with sufficient oxygen, how many moles of H₂O should form?

Aluminum metal reacts with sulfuric acid according to the following equation: 2Al(s)+ 3H₂SO₄(aq)→ Al₂(SO₄)₃(s)+ 3H₂(g)If 10.0 g of aluminum reacts with excess sulfuric acid, and 54.2 g of Al₂(SO₄)₃ are collected, what is the percent yield of Al₂(SO₄)₃?

Which of the following processes is endothermic?

Phosphorus trichloride can be made by the following reaction: P₄(s)+ 6Cl₂(g)→ 4PCl₃(l)What is the maximum amount of phosphorus trichloride that can be formed if 15 molecules of P₄ are mixed with 42 molecules of chlorine?

Which of the following is the best (simplest)balanced equation to represent the chemical reaction shown in the figure on any scale?

An energy input of 227 kJ is required to form acetylene from its elements. Convert this energy to units of calories.

Matter and Energy

Atoms, Ions, and the Periodic Table

Chemical Compounds

Chemical Composition

Chemical Reactions and Equations

Electron Structure of the Atom

Chemical Bonding

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The Liquid and Solid States

Solutions

Reaction Rates and Chemical Equilibrium

Acids and Bases

Oxidation-Reduction Reactions

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Exam 6: Quantities in Chemical Reactions

Given that 4NH3(g)+ 5O2(g)→ 4NO(g)+ 6H2O(g), if 8.2 moles of NH3 react with sufficient oxygen, how many moles of water should form?

Ammonia is usually made by the following reaction: N2(g)+ 3H2(g)→ 2NH3(g)What is the maximum amount of ammonia that can be formed if 30 molecules of nitrogen are mixed with 100 molecules of hydrogen?

The figure shows a molecular-level diagram of reactant molecules for the reaction: 2C2H2(g)+ 5O2(g)→ 4CO2(g)+ 2H2O(g) List the number and formulas of the molecules that should be present after the reaction takes place.

When mercury(II)oxide, a red crystalline solid, is heated, it decomposes to form liquid mercury and oxygen gas, according to the following equation: ___HgO(s)→ ___Hg(l)+ ___O2(g)(unbalanced)Balance the equation and determine the mass of mercury that should be formed when 15.6 g of HgO is heated.

Phosphine, PH3, a reactive and poisonous compound, reacts with oxygen as follows: 4PH3(g)+ 8O2(g)→ P4O10(s)+ 6H2O(g)If 15.0 g of phosphine reacts with sufficient oxygen, how many grams of P4O10 will be formed?

A 2.50 g sample of pitted prunes was burned in a bomb calorimeter containing 2110 g of water. The temperature of the water increased from 22.50°C to 25.76°C. How much heat, in joules, did the prune sample release when it burned? [Cwater = 4.184 J/(g°C)]

When mixed, solutions of silver nitrate, AgNO3, and sodium phosphate, Na3PO4, will form a precipitate of silver phosphate, Ag3PO4. The balanced equation is 3AgNO3(aq)+ Na3PO4(aq)→ Ag3PO4(s)+ 3NaNO3(aq)Which of the following statements regarding this reaction is incorrect?

The q value for the following reaction is 178.0 kJ for every mole of CaCO3 that reacts: CaCO3(s)→ CaO(s)+ CO2(g)How much heat would be required to decompose 4.00 mol CaCO3(s), and is the reaction endothermic or exothermic?

Consider the following specific heats of metals. If the same amount of heat is added to 25.0 g of each of these metals, all at the same initial temperature, which metal will have the highest final temperature?

Consider the reaction N2(g)+ O2(g)→ 2NO(g). The molecular image represents a mixture of N2(g)and O2(g)just before reaction occurs. What is the limiting reactant, and how much of the excess reactant remains after the reaction is complete? The image contains 2 N2 molecules and 4 O2 molecules.

When 5.0 g CaCl2 is dissolved in water, how many moles of ions are in solution?

Given that 4NH3(g)+ 5O2(g)→ 4NO(g)+ 6H2O(g), if 4.5 moles of NH3 react with sufficient oxygen, how many moles of H2O should form?

Aluminum metal reacts with sulfuric acid according to the following equation: 2Al(s)+ 3H2SO4(aq)→ Al2(SO4)3(s)+ 3H2(g)If 10.0 g of aluminum reacts with excess sulfuric acid, and 54.2 g of Al2(SO4)3 are collected, what is the percent yield of Al2(SO4)3?

Which of the following processes is endothermic?

Phosphorus trichloride can be made by the following reaction: P4(s)+ 6Cl2(g)→ 4PCl3(l)What is the maximum amount of phosphorus trichloride that can be formed if 15 molecules of P4 are mixed with 42 molecules of chlorine?

Which of the following is the best (simplest)balanced equation to represent the chemical reaction shown in the figure on any scale?

An energy input of 227 kJ is required to form acetylene from its elements. Convert this energy to units of calories.

Matter and Energy

Atoms, Ions, and the Periodic Table

Chemical Compounds

Chemical Composition

Chemical Reactions and Equations

Electron Structure of the Atom

Chemical Bonding

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Solutions

Reaction Rates and Chemical Equilibrium

Acids and Bases

Oxidation-Reduction Reactions

Nuclear Chemistry

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Filters

Given that 4NH₃(g)+ 5O₂(g)→ 4NO(g)+ 6H₂O(g), if 8.2 moles of NH₃ react with sufficient oxygen, how many moles of water should form?

Ammonia is usually made by the following reaction: N₂(g)+ 3H₂(g)→ 2NH₃(g)What is the maximum amount of ammonia that can be formed if 30 molecules of nitrogen are mixed with 100 molecules of hydrogen?

The figure shows a molecular-level diagram of reactant molecules for the reaction: 2C₂H₂(g)+ 5O₂(g)→ 4CO₂(g)+ 2H₂O(g) List the number and formulas of the molecules that should be present after the reaction takes place.

When mercury(II)oxide, a red crystalline solid, is heated, it decomposes to form liquid mercury and oxygen gas, according to the following equation: _HgO(s)→ _Hg(l)+ ___O₂(g)(unbalanced)Balance the equation and determine the mass of mercury that should be formed when 15.6 g of HgO is heated.

Phosphine, PH₃, a reactive and poisonous compound, reacts with oxygen as follows: 4PH₃(g)+ 8O₂(g)→ P₄O₁₀(s)+ 6H₂O(g)If 15.0 g of phosphine reacts with sufficient oxygen, how many grams of P₄O₁₀ will be formed?

A 2.50 g sample of pitted prunes was burned in a bomb calorimeter containing 2110 g of water. The temperature of the water increased from 22.50°C to 25.76°C. How much heat, in joules, did the prune sample release when it burned? [C_water = 4.184 J/(g°C)]

When mixed, solutions of silver nitrate, AgNO₃, and sodium phosphate, Na₃PO₄, will form a precipitate of silver phosphate, Ag₃PO₄. The balanced equation is 3AgNO₃(aq)+ Na₃PO₄(aq)→ Ag₃PO₄(s)+ 3NaNO₃(aq)Which of the following statements regarding this reaction is incorrect?

The q value for the following reaction is 178.0 kJ for every mole of CaCO₃ that reacts: CaCO₃(s)→ CaO(s)+ CO₂(g)How much heat would be required to decompose 4.00 mol CaCO₃(s), and is the reaction endothermic or exothermic?

When 5.0 g CaCl₂ is dissolved in water, how many moles of ions are in solution?

Given that 4NH₃(g)+ 5O₂(g)→ 4NO(g)+ 6H₂O(g), if 4.5 moles of NH₃ react with sufficient oxygen, how many moles of H₂O should form?

Aluminum metal reacts with sulfuric acid according to the following equation: 2Al(s)+ 3H₂SO₄(aq)→ Al₂(SO₄)₃(s)+ 3H₂(g)If 10.0 g of aluminum reacts with excess sulfuric acid, and 54.2 g of Al₂(SO₄)₃ are collected, what is the percent yield of Al₂(SO₄)₃?

Phosphorus trichloride can be made by the following reaction: P₄(s)+ 6Cl₂(g)→ 4PCl₃(l)What is the maximum amount of phosphorus trichloride that can be formed if 15 molecules of P₄ are mixed with 42 molecules of chlorine?