Redox Reactions

Which of following is incorrect about oxidation?

• Addition of oxygen

• Loss of electron

• Increase in oxidation state

• Addition of electopositive element

The reduction process involves

• Increase in oxidation number

• Decrease in oxidation number

• No change in oxidation number

• Sometimes increase and sometimes decrease in oxidation number

Which of the following represents a redox reaction?

• (a) NaOH + HCl → NaCl + H2O

• (b) BaCl2 + H2SO4 → BaSO4 + 2HCl

• (c) CuSO4 + 2H2O → Cu(OH)2 + H2SO3

• (d) Zn + 2HCl → ZnCl2 + H2

Which of following is correct about given reaction:-

Cl2 + H2S → S + 2HCl

• Cl2 is oxidising agent in the reaction.

• Cl2 undergo oxidation.

• H2S is oxidising agent.

• H2S undergo reduction

What is oxidation state of chlorine in Cl2 molecule ?

• -1

• 1

• -2

• 0

What is oxidation state of Sulphur in H2SO4 ?

• +6

• -6

• +4

• -4

Which oxidation state shown by alkali metals?

• -1

• +2

• -2

• +1

Which of following is incorrect about oxidation state?

• Oxidation state of all elements in their elemental form is taken as zero.

• For ions composed of only one atom, theoxidation number is equal to the chargeon the

• The algebraic sum of the oxidation numberof all the atoms in a compound must bezero.

• In metal hydrides oxidation state of Hydrogen is +1.

Oxidation state shown by alkaline earth metal is

• 1

• 2

• -1

• -2

What is oxidation state of oxygen in ozone (O3) molecule ?

• -2

• -1/2

• 0

• -1