One mole of N₂H₄ loses 10 moles of electrons to form a new compound Z. Assuming that all the nitrogens appear in the new compound, what is the oxidation state of nitrogen in Z? (There is no change in die oxidation state of hydrogen.)

• -1

• -3

• +3

• +5

A 100 mL solution of 0.1 N HCl was titrated with 0.2 N NaOH solution.The titration was discontinued after adding 30 mL of NaOH solution. The remaining titration was completed by adding 025 N KOH solution. The volume of KOH required for completing the titration is 

• 16 mL

• 32 mL

• 35 mL

• 70 mL

The gaseous products formed at cathode (X) and anode (Y), when an aqueous solution of sodium acetate is electrolysed are

• X	Y
  CO2	C2H6, H2

• X	Y
  H2, CO2	C2H6

• X	Y
  H2	C2H6, CO2

• X	Y
  C2H6, H2	CO2

In the chemical reaction, 

Cl₂ + H₂S → 2HCl + S.

The oxidation number of sulphur changes from

• 0 to 2

• 2 to 0

• -2 to 0

• -2 to -1

What is the oxidation number of chromium in potassium dichromate?

• +2

• +3

• +6

• -4

In the reaction,

3Mg + N₂ → Mg₃N₂

• magnesium is reduced

• magnesium is oxidised

• nitrogen is oxidised

• None of the above

Which of the following reactions is a redox reaction?

• 2AgNO₃ + BaCl₂ → 2AgCl + Ba(NO₃)₂

• BaO₂ + H₂SO₄  → BaSO₄ + H₂O₂

• P₂O₅ + 2H₂O  → H₄P₂O₇

• Cu + 2AgNO₃  → 2Ag + Cu(NO₃)₂

In the reaction 2Fe³⁺(aq) + Sn²⁺(aq) → 2Fe²⁺(aq) + A

A belongs to

• Sn⁴⁺(aq)

• Sn²⁺(aq)

• Sn³⁺(aq)

• Sn⁰

39.

For the redox reaction,

Zn (s) + Cu²⁺ (0.1M) → Zn²⁺ (1M) + Cu (s)

taking place in a cell, E${}_{\mathrm{cell}}^{°}$ is 1.10 V. E_cell for the cell will be $\left(2.303\frac{\mathrm{RT}}{\mathrm{F}} = 0.0591\right)$

• 2.14 V

• 1.80 V

• 0.82 V

• 1.07 V

Which of the following occurs at anode?

• Reduction

• Oxidation

• Both (a) and (b)

• None of these