Reactions Practice Test

1. Which substance can be decomposed chemically?

1. CaO and Ca 
2. MgO and Mg 
3. CO and Co 
4. CaO and MgO

2. The particles of a substance are arranged in a definite shape geometric pattern and are constantly vibrating. This substance can be in

1. The solid phase, only 
2. The liquid phase, only 
3. Either the liquid or the solid phase 
4. Neither the liquid or the solid phase

3. Given the balanced equation: Mg(s) + 2HCL(aq) –> MgCl₂(aq) + H₂(g)

At STP, what is the total number of liters of hydrogen gas produced when 3.00 moles of hydrochloric acid solution is completely consumed?

1. 11.2 L 
2. 22.4 L 
3. 33.6 L 
4. 44.8 L

4. Given the reaction at equilibrium: 2CO(g) + O2(g) –> 2CO₂(g)

When the reaction is subjected to stress, a change will occur in the concentration of

1. Reactants, only 
2. Products, only 
3. Both products and reactants 
4. Neither reactants nor products

5. What is the concentration of a solution of 10 moles of copper (II) nitrate in 5.0 liters of solution?

1. .50 M 
2. 2.0 M 
3. 5.0 M 
4. 10 M

6. What is the oxidation number of chlorine in HClO₄?

1. +1 
2. +5 
3. +3 
4. +7

7. Given the redox reaction: Fe²⁺(aq) + Zn(s) –> Zn²⁺(aq) + Fe(s)

Which species acts as a reducing agent?

1. Fe(s) 
2. Fe²⁺(aq) 
3. Zn(s) 
4. Zn²⁺(aq)

8. Given the reaction: Zn(s) + 2HCl(aq) –> ZnCl₂(aq) + H₂(g)

Which equation represents the correct oxidation half-reaction?

1. Zn(s) –> Zn²⁺ + 2e^– 
2. 2H + 2e^––> H₂(g) 
3. Zn²⁺ + 2e –> Zn(s) 
4. 2Cl^– –> Cl₂(g) + 2e^–

9. Which of the following is the strongest Bronsted acid?

1. NH 
2. HSO 
3. H 
4. HNO₃

10. What is the pH of a solution with a hydronium ion concentration of .01 mole per liter?

1. 1 
2. 2 
3. 10 
4. 14

11. Which terms describe a substance that has a low melting point and poor electrical conductivity?

1. Covalent and metallic 
2. Covalent and molecular 
3. Ionic and molecular 
4. Ionic and metallic

12. Given the reaction: 4NH₃ + 5O₂ –> 4NO + 6H₂O 

What is the maximum number of moles of H₂O that can be produced when 2.0 moles of NH₃ are completely reacted?

1. 1.0 
2. 2.0 
3. 3.0 
4. 6.0

13. Which compound is a salt?

1. Na₃PO₄ 
2. H₃PO₄ 
3. CH₃COOH 
4. Ca(OH)₂

14. At 1 atm and 298 K, which of the K_a values listed below represents the strongest acid?

1. 1.1 x 10^-7 
2. 1.8 x 10^-5 
3. 5.6 x 10^-11 
4. 4.6 x 10^-4

15. Which compound will conduct an electric current when dissolved in water?

1. NaOH 
2. C₂H₅OH 
3. C₆H₁₂O₆ 
4. C₁₂H₂₂O₁₁

16. Which half reaction correctly represents oxidation?

1. Sn²⁺ + 2e –> Sn⁰ 
2. Sn⁴⁺ + 2e^– –> Sn²⁺ 
3. Sn² –> Sn⁰ + 2e 
4. Sn²⁺ –> Sn⁴⁺ + 2e

17. In a redox reaction the reducting agent will

1. Lose electrons and be reduced 
2. Lose electrons and be oxidized 
3. Gain electrons and be reduced 
4. Gain electrons and be oxidized

18. A reaction will be spontaneous if it results in product that have

1. Lower potential energy and less randomness 
2. Lower potential energy and more randomness 
3. Greater potential energy and less randomness 
4. Greater potential energy and more randomness

19. Which of the following does not have a strong K_a value?

1. Boric Acid 
2. Nitric Acid 
3. Sulfuric Acid 
4. Chloric Acid

20. If the pH is greater than 7 litmus paper will turn ____.

1. Red 
2. Orange 
3. Neutral 
4. Blue

Answer Key

1. D 
2. A 
3. C 
4. C 
5. B 
6. D 
7. C 
8. A 
9. A 
10. B 
11. B 
12. C 
13. A 
14. D 
15. A 
16. D 
17. B 
18. B 
19. A 
20. D