Oxidation and Reduction Agents

What is oxidation number of P in K₃PO₄?

• +1
• +5
• -2
• 0

What is oxidation number of Ca in CaCl₂ ?

• -1
• -2
• +1
• +2

What is oxidation number of O in O₂ ?

• 0
• -2
• +1
• +2

What is oxidation number of Na in Na⁺ ?

• 0
• +1/2
• +1
• -1

What is the oxidation number of Ca in Ca₃N₂?

• +3
• +2
• -3
• -2

What element always has an oxidation number of -1?

• Hydrogen
• Fluorine
• Chlorine
• Iodine

What is the oxidation number of Br in BrO₃^-1?

• +3
• -2
• +5
• +2

     In the reaction Zn + H₂O --> ZnO₂ + H₂
 which element, if any, is oxidized? 

• Zinc
• Hydrogen
• Oxygen
• None

In the reaction
2Ca(s) + O₂(g) --> 2CaO(s), calcium is __________

• Reduced
• Synthesized
• Oxidized
• None of the above

Oxidation involves

• gaining electrons; gaining oxygen
• losing electrons; losing oxygen
• gaining electrons; losing oxygen
• losing electrons; gaining oxygen