U5.2 Oxidation state

Oxidation is the _________ of electrons.

• loss

• gain

• sharing

• transfer

Reduction is the ___________ of electrons.

• loss

• gain

• sharing

• transfer

Which of the following represents oxidation?

• C → CH₄

• Fe³⁺ → Fe²⁺

• Cl₂ → 2Cl^-

• Zn → ZnO

Which statement is true:
Mg → Mg²⁺ + 2e^–

• Mg gains 2 electrons
• Mg_²⁺ loses 2 electrons
• Mg loses 1 electron
• Mg loses 2 electrons

What is the oxidation number of O in CO₂?

• +2
• -1
• +4
• -2

The sum of all oxidation numbers in a neutral compound is ___.

• 0
• 1
• -1
• depends on the compound

What is oxidation number of Mn in MnO₂ ?

• 0
• +2
• -2
• +4

What is the oxidation number of Ca in Ca₃N₂?

• +3
• +2
• -3
• -2

What is the oxidation state of Cu in Cu²⁺?

• -1

• -2

• +2

• 0

H in NaH ?

• +1

• 0

• -1

• None of the above