Redox Quiz-1

1. If an atom is reduced in a redox reaction, what must happen to another atom in the system?a. It must be oxidized.b. It must be reduced.c. It must be neutralized.d. Nothing needs to happen to another atom in the system.

2. What is another name for an oxidation-reduction reaction?a. O-reaction c. redox reactionb. R-reaction d. oxred reaction

3. Oxidation is ____.a. a loss of oxygen c. a loss of electronsb. a gain of electrons d. a gain of hydrogen

4. In the reaction of sodium with oxygen, which atom is reduced?a. sodium c. both a and bb. oxygen d. neither a nor b

5. type of reaction does Sn Sn represent?a. oxidation c. hydrolysisb. reduction d. none of the above

6. In the reaction of calcium with chlorine, which atom is the oxidizing agent?a. calcium c. both a and bb. chlorine d. neither a nor b

7. In the reaction of hydrogen with iodine, which atom is oxidized?a. hydrogen c. both a and bb. iodine d. neither a nor b

8. Cu Cu + 2 e-The equation above represents the type of reaction called ____.a. redox c. reductionb. hydrolysis d. oxidation

9. What is the reducing agent in the following reaction?

2Na + 2H O 2NaOH + Ha. Na c. NaOH

b. H O d. H

10. What is the oxidizing agent in the following reaction?

I + MnO I + MnO

a. I c. I

b. MnO d. MnO

11. The oxidation number of magnesium in magnesium chloride is ____.a. –1 c. +1b. 0 d. +2

12. The oxidation number of bromime in bromime gas is ____.a. –2 c. 0b. –1 d. +1

13. What is defined as the charge an atom would have in a compound if its bonding electrons were assigned to the more electronegative atom?a. reduction number c. valenceb. oxidation number d. electropositivity

14. In which of the following compounds is the oxidation number of nitrogen different from the other three?

a. NO c. NH Cl

b. N O d. Ca(NO )

15. Which atom has a change in oxidation number of –3 in the following redox reaction?

K Cr O + H O + S KOH + Cr O + SOa. K c. Ob. Cr d. S

16. In the following unbalanced reaction, which atom is oxidized?

HNO + HBr NO + Br + H Oa. hydrogen c. oxygenb. nitrogen d. bromine

17. Which element increases its oxidation number in the following reaction?

3KOH + H PO K PO + 3H Oa. potassiumb. hydrogenc. oxygend. No element increases its oxidation number.

18. What coefficient of H balances the atoms in the following half-reaction?

H + MnO Mn + H Oa. 1 c. 3b. 2 d. 4

19. What is the oxidation half-reaction for the following unbalanced redox equation?

Cr O + Fe Cr + Fe

a. Cr Cr O c. Fe Fe

b. Fe Fe d. Cr O Cr

20. Which oxidation-reduction reactions are best balanced by the half-reaction method?a. covalent reactions c. ionic reactionsb. acid-base reactions d. intermolecular reactions