Introduction to Le Chatelier's Principle

Q.

What happens to equilibrium when inert gas is added?

Q. ctabie11. The equilibrium constant for the reaction, H2(g) + 12(g)2HI(g)is 32 at a given temperature. The equilibrium concentration of 2 and HI are 0.5 x 10- and8 10-3 M respectively. The equilibrium concentration of H2 is(1) 1 x 10-3 M(2) 0.5 x 10-3 M(4) 4\ast 10-3 M(3) 2x 10-3

Q.

For conversion C (graphite ) $⟶$ C (diamond ) the $\Delta S$ is

1. Zero

2. Unknown

3. Negative

4. Positive

Q.

Le-chatelier principle is applicable

1. Both for physical and chemical equilibrium

2. Only for chemical equilibrium

3. Only for physical equilibrium

4. Neither for physical nor for chemical equilibrium.

Q. Suppose the reaction $PC{l}_5\left(g\right)$ $\rightleftharpoons$ $PC{l}_3\left(g\right)$+ $C{l}_2\left(g\right)$ as equlibirium in closed vessel. What is the effect on equilibirium concentration of the $C{l}_2\left(g\right)$ by adding $PC{l}_5$ at constant temperatue

1. Decrease
2. Increase
3. Unaffected
4. Can not be described without the value of $K_p$

Q. In a 2 L flask, the reaction takes place as:
$COC{l}_2\left(g\right)\rightleftharpoons CO\left(g\right)+C{l}_2\left(g\right)$
The equilibrium concentration of $\left[COC{l}_2\right]$ was found to be 0.4 M. If an excess of $COC{l}_2$ is added to the system, the equilibrium reestablishes and $\left[COC{l}_2\right]$ becomes 1.6 M. What is the equilibrium concentration of $\left[CO\right]$?

1. Half of the former value
2. Thrice of the former value
3. Remains unaltered
4. Twice of the former value

Q.

According to Le-chatelier principle, if heat is given to solid-liquid system,

then

1. Quantity of liquid will reduce

2. Quantity of solid will reduce

3. Increase in temperature

4. Decrease in temperature

Q.

Following gaseous reaction is undergoing in a vessel $C_2{H}_4+H_2\rightleftharpoons C_2{H}_6;\Delta H=-32.7Kcal$. Which will increase the equilibrium concentration of $C_2{H}_6$ ?

1. Increase of temperature

2. By reducing temperature

3. By removing some hydrogen

4. By adding some $C_2{H}_6$

Q.

How Does Temperature Change Equilibrium?

Q. The volume of 0.0618 mol of O2 obtained by decomposition of KCLO3 and collected by displacement of water of 428 ml at a pressure of 754 mmHg at 25 celsius. The pressure of water vapour at 25 celsius

Q.

6. Write one of the reaction for each of the following characteristics :

(e) Evolution of heat

Q. What will happen when the pressure is applied on a $ice\rightleftharpoons water$ system ?

1. More water will form
2. More ice will form
3. There will be no effect over equilibrium
4. 
   Water will decompose in $H_2$and $O_2$
   

Q. According to Le Chateliers principle adding heat to a solid and liquid in equilibrium will cause the a) temperature to increase b) temperature to decrease C) amount of liquid to decrease d) amount of solid to decrease

Q.

When hydrochloric acid is added to cobalt nitrate solution at room temperature, the following reaction takes place and the reaction mixture becomes blue. On cooling the mixture, it becomes pink. On the basis of this information mark the correct answer.

$\left[\mathrm{CO}{\left({\mathrm{H}}_2\mathrm{O}\right)}_6{]}_3\right(\mathrm{aq})+4{\mathrm{Cl}}^{-}(\mathrm{aq})\leftrightharpoons {{\left[{\mathrm{COCl}}_4\right]}^2}^{-}(\mathrm{aq})+6{\mathrm{H}}_2\mathrm{O}(\mathrm{l}):$

1. $△\mathrm{H}<0\mathrm{for}\mathrm{the}\mathrm{reaction}$

2. $△\mathrm{H}>0\mathrm{for}\mathrm{the}\mathrm{reaction}$

3. $△\mathrm{H}=0\mathrm{for}\mathrm{the}\mathrm{reaction}$

4. None of these

Q. For the chemical reaction $3X\left(g\right)+Y\left(g\right)\rightleftharpoons X_{3}Y\left(g\right)$ at equillibrium is affected by

1. Temperature and pressure

2. Temperature only

3. Pressure only
4. Temperature, pressure and catalyst

Q.

H₂ + S ⇌ H₂S + Energy
What would shift the equilibrium to the right?

1. adding hydrogen sulphide gas

2. adding heat

3. removing hydrogen

4. removing hydrogen sulphide gas

Q. For the equilibrium:
$PC{l}_5\left(g\right)\rightleftharpoons PC{l}_3\left(g\right)+C{l}_2\left(g\right)$
If the equilibrium concentration of $PC{l}_5\left(g\right)$ is doubled, the concentration of $C{l}_2\left(g\right)$ will be

1. $\frac{1}{2}$ of original value
2. $\frac{1}{4}$ of original value
3. $\frac{1}{8}$ of original value
4. None of these

Q.

For thedecomposition reaction 4$HN{O}_3$ (g) $\leftrightharpoons$ 4$N{O}_2$ (g) + 2$H_2$ O (g) + $O_2$ (g) if we start with only the reactant $HN{O}_3$ and p = equilibrium pressure, the equilibrium constant $K_p$ is:

1. =
   

2. = 1024
   

3. = 7
   
   
   
   
   
   
   

4. =

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Q. Which of the following conditions will favour the maximum formation of the product in the reaction:
$A_2$(g) + $B_2$(g) $\rightleftharpoons$ $X_2$(g) ${△}_r$H= -X kJ

1. High temperature and high pressure
2. Low temperature and low pressure
3. Low temperature and high pressure
4. High temperature and low pressure

Q. Dihydrogen gas is obtained from natural gas by partial oxidation with steam as per following endothermic reaction:

Q.

For the reaction $H_2$ (g) + $I_2$ (g) $\leftrightharpoons$ 2HI(g)the equilibrium constant $K_p$ changes with

1. the amounts of and present

2. temperature

3. Total pressure

4. catalyst

Q. 32. Describe the main features of theVSEPR theory . andWhat is dipole moment

Q. Following two equilibrium is simultaneously established in a container.
$PC{l}_5\left(g\right)\rightleftharpoons PC{l}_3\left(g\right)+C{l}_2\left(g\right)$
$CO\left(g\right)+C{l}_2\left(g\right)\rightleftharpoons COC{l}_2\left(g\right)$
If some $Ni\left(s\right)$ is introduced in the container forming $Ni\left(CO{)}_4\right(g)$ then at new equilibrium:

1. $PC{l}_3$ concentration will increase
2. $PC{l}_3$ concentration will decrease
3. $C{l}_2$ concentration will remain same
4. $CO$ concentration will remain same

Q. When hydrochloric acid is added to cobalt nitrate solution at room temperature, the following reaction takes place and the reaction mixture becomes blue. On cooling the mixture it becomes pink. On the basis of this information mark the correct answer.

$\underset{pink}{\underset{}{\left[Co\right(H_{2}O{)}_6{]}^{3^{+}}\left(aq\right)}}+4C{l}^{-}\left(aq\right)\leftrightharpoons \underset{blue}{\underset{}{\left[C_{o}C{l}_4{]}^{2^{-}}\right(aq)}}+6H_{2}O\left(l\right)$

1. $△H>o$ for the reaction
2. $△H<o$ for the reaction
3. $△H=o$ for the reaction
4. The sign of $△H$ canot be predicted on the basis of this information

Q. Which of the following conditions is favourable for the production of ammonia by Haber`s process?

1. High concentration of reactants
2. Low temperature and high pressure
3. Continuous removal of ammonia
4. All of these

Q. The effect of increasing the pressure on the equilibrium $2A\left(g\right)+3B\left(g\right)\rightleftharpoons 3A\left(g\right)+2B\left(g\right)$ is

1. Forward reaction is favoured
2. Backward reaction is favoured
3. No effect
4. None of the above

Q.

Ice and water are placed in a closed container at a pressure of 1 atm and temperature 273.15 K. If pressure of the system is increased to 2 atm while keeping temperature constant, which of the following would be the correct observation ?

1. The liquid phase disppears completely

2. The amount of ice decreases

3. The solid phase (ice) disappears completely

4. Volume of the system increases

Q. In the reaction, $2S{O}_2\left(g\right)+O_2\left(g\right)\rightleftharpoons 2S{O}_3\left(g\right)+X\text{cal}$, most favourable conditions of temperature and pressure for greater yield of $S{O}_3$ are:

1. Low temperature and low pressure
2. High temperature and low pressure
3. High temperature and high pressure
4. Low temperature and high pressure