Effect on Kc

Q.

What is the relation between ∆H and ∆U?

1. ∆H = ∆U - RT

2. ∆H = ∆U + RT

3. ∆H = ∆U + ∆nRT

4. ∆H = ∆U

Q.

$H_2+I_2=2HI$ In the above equilibrium system if the concentration of the

reactants at ${25}^{\circ }C$is increased, the value of $K_C$ will

1. Increase

2. Decrease

3. Remains the same

4. Depends on the nature of the reactants

Q.

Regarding the rate of a reversible reaction, the correct explanation of the effect

of catalyst is

1. It decreases the velocity of backward reaction

2. It provides a new reaction path of low activation energy

3. It increases the kinetic energy of reacting molecules

4. It displaces the equilibrium state on right side

Q.

The equilibrium constant Kp of the reaction, 2$S{O}_2$(g) + $O_2$(g) \(\leftrightharpoons\) 2$S{O}_3$(g) is 900 atm. at 800 K. A mixture containing $S{O}_3$and $O_2$ having initial pressure of 1 and 2 atm respectively is heated at constant volume to equilibrate. Calculate the partial pressure of $S{O}_2$ gas at 800 K.

1. 0.0236 atm

2. 0.05 atm

3. 1.03 atm

4. 0.442 atm

Q.

For the reaction $N_2\left(g\right)+3H_2\left(g\right)\rightleftharpoons 2N{H}_3\left(g\right),\Delta H=-93.6kJmo{l}^{-1}$. The amount (i.e. number of mole) of~$H_2$ at equilibrium will
increase if

1. Volume is increased

2. Volume is decreased

3. is added at constant volume

4. is removed.

Q. The $E_{\text{cell}}^0$ for the given cell reaction is $-0.32\text{V}$ at ${25}^{\circ }\text{C}$.
$Fe\left(s\right)+Z{n}^{2+}\left(aq\right)\rightleftharpoons Zn\left(s\right)+F{e}^{2+}\left(aq\right)$
What will be the value of $\log \left[F{e}^{2+}\right]$ at equilibrium when a piece of iron is placed in a $1\text{M}$ of $Z{n}^{2+}$ solution?

1. $+5.42$
2. $-10.83$
3. $-5.42$
4. $+10.83$

Q.

Regarding the rate of a reversible reaction, the correct explanation of the effect

of catalyst is

1. It provides a new reaction path of low activation energy

2. It increases the kinetic energy of reacting molecules

3. It displaces the equilibrium state on right side

4. It decreases the velocity of backward reaction

Q. A vessel has nitrogen gas and water vapours are at total pressure 1atm. The partial pressure of water vapours is 0.3 atm. The contents of this vessel are transferred to another vessel having one third of capacity of original volume, completely at the same temperature the what is total pressure of the system in new vessel

Q. For the reaction: $H_2\left(g\right)+I_2\left(g\right)\rightleftharpoons 2HI\left(g\right)$ the equilibrium constant $K_p$ changes with

1. total pressure
2. catalyst
3. the amounts of $H_2$ and $I_2$ present
4. temperature

Q. $A\left(g\right)+3B\left(g\right)\rightleftharpoons 4C\left(g\right)$
Initial concentration of A is equal to that of B. The equilibrium concentration of A and C are equal. $K_c$ of the reaction will be:

1. $0.08$
2. $0.8$
3. $8$
4. $80$

Q. The equilibrium,
$N{H}_{4}HS\left(s\right)\rightleftharpoons N{H}_3\left(g\right)+H_{2}S\left(g\right)$, is followed to set-up at $127{}^{\circ }\text{C}$ in a closed vessel. The total pressure at equilibrium was $20\text{atm}$. The $K_c$ for the reaction is:
(Given $R=0.08{\text{L atm K}}^{-1}{\text{mol}}^{-1}$)

1. $0.097{\text{M}}^2$
2. $0.085{\text{M}}^2$
3. $3.045{\text{M}}^2$
4. $1.04{\text{M}}^2$

Q. Two weak bases $AOH$ and $BOH$ having equal concentrations of $0.5M$ are present in a solution. Calculate the ratio, $\frac{\left[A^{+}\right]}{\left[B^{+}\right]}$ at equilibrium.
Dissociation constants for $AOH$ and $BOH$ are $1.1\times {10}^{-8}$ and $1.7\times {10}^{-9}$ respectively.(Report the answer upto second decimal)

Q. For the reaction $3A\left(g\right)+B\left(g\right)\rightleftharpoons 2C\left(g\right)$ at a given temperature, $K_c=90$.What must be the volume of the flask, if a mixture of $2.0mol$ each of $A,B$ and $C$ exist in equilibrium?

1. $6L$
2. $9L$
3. $36L$
4. None of these

Q. An increase in pressure in this reaction would:

1. produce more $I^{-}\left(aq\right)$
2. drive it to the right
3. produce more $H_2$
4. not affect the system