# HSC Chemistry - 12th One Mark Questions - Model

This post is specific to important one mark questions focussing chemistry.15 sample questions collected from a random question bank this time, to test your knowledge on the subject. If you are ready, get going. Make sure that you post your answers in the comments section.

1) The Bragg’s equation is:

a) $\lambda =2d \; sin\theta$

b) $nd =2\lambda \; sin\theta$

c) $\lambda=nd \; sin\theta$

d) $n\lambda=2d \; sin\theta$

2) The temperature at which the resistance of the material is suddenly changed to zero is:

a) critical temperature

b) transition temperature

c) absolute temperature

d) conducting temperature

3) What is the entropy change for the vaporization of water at 100 degree C if the molar enthalpy of vaporization is $40.627 kJ \; mol^{-1}$?

a) $406.27 kJ \; mol^{-1}$

b) $108.87 J \; mol^{-1}$

c) $606.27 J \; mol^{-1}$

d) $808.27 J \; mol^{-1}$

4) Which one of the following can be used as a catalyst in Haber’s process?

a) Pt

b) Pd

c) Fe

d) Ni

5) At chemical equilibrium \Delta G is:

a) positive

b) negative

c) zero

d) none of these

6) The degree of dissociation of $PCI_{5}$ at 1 atm and 298 K is 0.2. The value of $K_{p}$ is:

a) 0.42 atm

b) 0.24 atm

c) 0.48 atm

d) 0.042 atm

7) What is the the active mass of 96 g of oxygen in 2 litre flask?

a) $16 \;mol/litre^{-1}$

b) $3 \;mol/litre^{-1}$

c) $2 \;mol/litre^{-1}$

d) $1.5 \;mol/litre^{-1}$

8) When $\Delta G>0$, the process is:

a) spontaneous

b) feasible

c) non-feasible

d) equilibrium

9) How many atoms are there in a unit cell of a metal crystallizing in fcc structure?

a) 6

b) 2

c) 4

d) 1

10) The number of positive ions are slight excess than the number of negative ions in:

a) Frenkel defect

b) Schottky defect

c) Line defect

d) Metal excess defect

11) The final temperature of an engine whose initial temperature is 400 K and having 25% efficiency is:

a) 200 K

b) 400 K

c) 300 K

d) 450 K

12) X-rays of wavelength 0.15 nm are used in an X-ray diffraction experiment. First order reflection is observed when the angle of incidence $\theta$ is 100 02’. The interplanar distance in the crystal used will be:

a) 4.32 nm

b) 0.342 nm

c) 0.432 nm

d) 0.234

13) The relation $\Delta G=\Delta H - T\Delta S$ was given by:

a) Boltzman

c) Gibbs Helmholtz

d) Thomson

14) If the latent heat of fusion of ice is $6.025 kJ \; mol^{-1}$, what will be its entropy of fusion?

a) $22.07 JK^{-1} \; mol^{-1}$

b) $22.07 kJK^{-1} \; mol^{-1}$

c) $2.07 JK^{-1} \; mol^{-1}$

d) $2.07 JK^{-1} \; mol^{-1}$

15) In a chemical reaction, the rate constant of backward reaction is $7.5\times10^{-4}$ and the equilibrium constant K = 1.5. What is the rate constant of forward reaction?

a) $1.125\times10^{-3}$

b) $11.25\times10^{-3}$

c) $0.125\times10^{-3}$

d) $125\times10^{-3}$