11.

The molarity of a 0.2 N Na₂CO₅ solution will be :

• 0.05 M

• 0.2 M

• 0.4 M

• 0.1 M

A bottle of cold drink contains 200 ml liquid in which CO₂ is 0.1 molar .Suppose CO₂ behaves like an ideal gas , the volume of the dissolved CO₂ at STP is :

• 0.224 L

• 22.4 L

• 0.448 L

• 44.8 L

Diborane is used for reduction of :

• carboxylic acids

• esters

• nitro groups

• Both (a) and (b)

If a salt bridge is removed between the half cells , the voltage :

• decreases to zero

• increases

• increases rapidly

• do not change

Lanthanum the first element of lanthanide series has :

• only unfilled 3d orbitals

• unfilled 3d and 4d orbitals

• unfilled 4d and 4forbitals

• unfilled 4f and 5d orbitals

A radioactive substance decays $\frac{3}{4}$th of it original value in 2h. The half-life of the substance is :

• 1 h

• 30 min

• 20 min

• 15 min

The chemical reaction 2O₃ $\to$3O₂ proceeds as :

(I) O₃ $\rightleftharpoons$ O₂ + O (fast)

(II) O + O₃ $\to$ 2O₂ (slow)

The rate expression should be :

• r = k[O₃]²

• r = k[O₃]² [O₂]^-1

• r = k[O₃] [O₂]

• None of these

Which of the following has more unpaired d-electrons ?

• Zn

• Fe²⁺

• Ni³⁺

• Cu⁺

How many structural isomers are possible for C₄H₉Cl ?

• 2

• 4

• 8

• 10

0.5 molal solution of ethylene glycol in water is used as coolant in car .If the freezing point depression constant ofwater is l.86°C per mol , the mixture will freeze at :

• 0.93 °C

• - 0.93 °C

• 1.86 °C

• - 1.86 °C