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## Oxidation Number MCQs

**1. In NaH, the oxidation state of hydrogen is _______________**

a) 2

b) 1

c) -1

d) 0

**Answer: **-1

**2. What is the oxidation state of Cr in CrO5?**

a) 3

b) 4

c) 5

d) 6

**Answer: **6

**3. What is the oxidation state of C in C3O2?**

a) 0

b) 2

c) -2

d) 0, 2, 2

**Answer: **0, 2, 2

**4. What is the oxidation state of N in NH4NO3 (in order)?**

a) -3, 5

b) 5, -3

c) 5

d) -3

**Answer: **-3, 5

**5. What is the average oxidation state of S in Na2S6O6?**

a) 5

b) 0

c) 5/2

d) 2

**Answer: **5/2

**6. What is the stock notation of cuprous oxide?**

a) copper oxide

b) copper (I) oxide

c) copper 1 oxide

d) copper 2 oxide

**Answer: **copper (I) oxide

**7. What is the stock notation of mercuric chloride?**

a) Mercury

b) Mercuric chloride

c) Chloride

d) Mercury (II) chloride

**Answer: **Mercury (II) chloride

**8. Can 1/2 be an oxidation number?**

a) yes

b) no

c) may be

d) cannot say

**Answer: **yes

**9. The oxidation number of oxygen in Ozone is 1, -1 and 0.**

a) true

b) false

**Answer: **true

**10. Helium element has an Oxidation state of ____________**

a) 2

b) 0

c) 1

d) -1

**Answer: **0