31.

The Ka of an acid is 3.2 x 10^-5. The degree of dissociation of the acid at concentration of 0.2 M is

• 6.0 x 10^-2

• 1.26 x 10^-2

• 4.0 x 10^-2

• 0.04 x 10^-3

Which of the following dissolves in hot conc. NaOH solution?

• Fe

• Zn

• Cu

• Ag

Which of the following statement is not correct?

• Adsorption energy for chemical adsorption is generally greater than that of physical adsorption

• Physical adsorption is due to van der Waal forces

• Physical adsorption decreases at high temperature and low pressure

• Physical adsorption is irreversible

For a reaction, the half-life is independent of initial concentration. What is the order of that reaction?

• Zero

• One

• Two

• Three

Addition of a non-volatile solute causes lowering in vapour pressure of a solvent from 0.8 atm to 0.2 atm. What is the
mole fraction of solvent?

• 0.25

• 0.75

• 0.50

• Cannot be predicted

Two metals 'A' and 'B' have E${}_{\mathrm{red}}^{°}$, value equal to 0.36 V and 1.23 V. What will be the correct cell equation?

• A + B²⁺ $\to$ A²⁺ + B

• A²⁺ + B $\to$ A + B²⁺

• Both (a) and (b)

• None of the above

Which of the following forms molecular solid?

• SO₂

• SiO₂

• SiC

• Diamond

Solvent loving colloids are known as

• hydrophobic

• lyophilic

• hydrophilic

• none of these

Which of the following, is a mordant dye?

• Aniline black

• Congo-red

• Alizarin

• Indigo

The compound which reacts faster with Lucas reagent is

• butan-1-ol

• butan-2-ol

• 2-methyl-propan-1-ol

• 2-methyl propan-2-ol