Characteristics of Chemical Equilibrium

Q. The vapour density of $N_2{O}_4$ at a certain temperature is 30. What is the percentage dissociation of $N_2{O}_4$ at this temperature?

1. 53.3%
2. 76.6%
3. None of the above
4. 26.7%

Q. Volume of CO2 obtained at STP by the complete decomposition of 9.85 gm BaCO3 is

Q. If $PC{l}_5$ is 80% dissociated at 523 $K$, what is the vapour density of the equilibrium mixture at 523 $K$ ?

1. 57.92
2. 67.92
3. 77.93
4. 45.45

Q. Which of the following is true at equilibrium?

1. The reaction stops at equilibrium
2. The rate of forward reaction is greater than the rate of the reverse reaction.
3. Amounts of reactants and products are equal.
4. Amount of reactants and products are constant.

Q. What is kp and kc

Q. Calculate the weight of non - volatile solute having molecular weight $40$, which should be dissoved in $57\text{g}$ octane to reduce its vapour pressure to $80\%$.

1. $2.5\text{g}$
2. $5\text{g}$
3. $0.66\text{g}$
4. $10g$

Q. 14.The rate law for the reaction, RCl + NaOH(aq)-ROH + NaCl is given by Rate=k(RCl).The rate of reaction will be 1)Doubled on doubling the concentration of NaOH 2)Halved on reducing the concentration of alkyl halide to one half 3)Decreases on increasing the temperature 4)Unaffected by increasing the temperature

Q. Ammonium carbamate when heated to ${200}^{0}C$ gives a mixture of $N{H}_3$ and $C{O}_2$ with vapour density of 13.
$N{H}_2-\stackrel{\stackrel{O}{||}}{C}-ON{H}_4\left(s\right)\rightleftharpoons 2N{H}_3\left(g\right)+C{O}_2\left(g\right)$
The degree of dissociation of ammonium carbonate is:

1. 0.75
2. 0.9
3. 1
4. 0.5

Q. A cylinder filled with a movable piston contains liquid water in equilibrium with water vapour at 25°c . Which one of the following operations results in a decrease in equilibrium vapour pressure?
1. Moving piston downward a short distance
2. Removing a small amount of vapour
3. Removing a small amount of the liquid water
4. Dissolving salt in the water

Q. For which of the following reactions, the degree of dissociation cannot be calculated from the vapour density data
$I.2H{I}_{\left(g\right)}\rightleftharpoons H_{2\left(g\right)}+I_{2\left(g\right)}$
$II.2N{H}_{3\left(g\right)}\rightleftharpoons N_{2\left(g\right)}+3H_{2\left(g\right)}$
$III.2N{O}_{\left(g\right)}\rightleftharpoons N_{2\left(g\right)}+O_{2\left(g\right)}$
$IV.PC{l}_{5\left(g\right)}\rightleftharpoons PC{l}_{3\left(g\right)}+C{l}_{2\left(g\right)}$

1. I and III
2. II and IV
3. I and II
4. III and IV

Q.

What do you mean by Static Equilibrium?

Q.

How Does The EMF Change With Temperature?

Q. 16 moles of $H_2$ and 4 moles of $N_2$ are sealed in a one litre vessel. The vessel is heated at a constnat temperature until the equilibrium is established, it is found that the pressure in the vessel has fallen to 9/10 of its original value. Calculate newly concentration of $N_2$ and $N{H}_3$ in $mol{L}^{-1}$
$N_{2\left(g\right)}+3H_{2\left(g\right)}\rightleftharpoons 2N{H}_{3\left(g\right)}$

Q.

In a gas phase reaction, the decomposition of ${\mathrm{PCl}}_5$ takes place at $273°\mathrm{C}$ and 1 atmospheric pressure. Its percentage degree of dissociation is 40 per cent. Assuming that all gases in the reaction behave ideally, calculate the density of the equilibrium mixture. [atomic weight of phosphorus $=31.0$ and chlorine $=35.5$ ]

Q. The equilibrium constant for the reaction is $H_2+B{r}_2\to 2HBr$ at 1024 k is $1.60\times {10}^5.$ Find the equilibrium pressure of all gases if $10bar$ of HBr is introduced into a sealed container at $1024K$.

1. $10bar$
2. $20bar$
3. $15bar$
4. $17bar$

Q.

$H_2\left(g\right)+I_2\left(g\right)\rightleftharpoons 2HI\left(g\right)$

When 46g of I2and 1g of H2are heated at equilibrium at ${450}^{\circ }C$, the equilibrium mixture contained 1.9g of I2.

How many moles of $I_2$ and HI are present at equilibrium.

1. 0.0075 & 0.347 moles

2. 0.0052 & 0.347 moles

3. 0.0075 & 0.147 moles

4. 0.0050 & 0.147 moles

Q.

What is equilibrium and why is it important?

Q. Statement 1: For a chemical reaction at initial stage rate of forward reaction $\left(r_f\right)$ is greater than rate of reversed reaction $\left(r_b\right)$
Statement 2: When $r_f=r_b,$ chemical reaction is at equilibrium.

1. Statement 1 is true but statement 2 is wrong
2. Statement 2 is true but statement 1 is wrong
3. Both statement are true
4. None of above statement are true

Q. In the chemical reaction $A\rightleftharpoons B$, the system is said to be in equilibrium when:

1. $A$ completely changes to $B$
2. $50\%$ of $A$ changes to $B$
3. The rate of change of $A$ to $B$ and $B$ to $A$ are same
4. Only $10\%$ of $A$ changes to $B$

Q. Which of the following is not a general characteristic of equilibrium involving physical processes?

1. Equilibrium is possible only in a closed system at a given temperature
2. All measurable properties of the system remain constant
3. All the physical processes stop at equilibrium
4. The opposing processes occur at the same rate and there is a dynamic but a stable condition

Q. Pure phosphine originally present at $2.5atm$ and $300K$ decomposes slowly according to the equation:
$4P{H}_3\left(g\right)\rightleftharpoons P_4\left(g\right)+6H_2\left(g\right)$
What is the vapour density of phosphine if it dissociates to the extent of 40%?

1. 13.07
2. 22.17
3. 18.07
4. 19.2

Q. Consider the reaction A $\to$ B, graph between half life $t_{1/2}$ and initial concentration (a) of the reactant is

Hence graph between $-\frac{d\left[A\right]}{dt}$ and time will be

1. 
2. 
3. 
4. 

Q.

What is the Equilibrium that exists between a liquid and its vapour?

Q.

What is equilibrium mean?

Q. Which of the following is true at equilibrium?

1. The reaction stops at equilibrium
2. The rate of forward reaction is greater than the rate of the reverse reaction.
3. Amounts of reactants and products are equal.
4. Amount of reactants and products are constant.

Q. In the chemical reaction,
$N_2\left(g\right)+3H_2\left(g\right)\rightleftharpoons 2N{H}_3\left(g\right)$
at equilibrium point:

1. Equal masses of $N_2$ and $H_2$ are reacting
2. Equal volumes of $N_2$ and $H_2$ are reacting
3. The reaction has stopped
4. The same amount of ammonia is formed as it is decomposed into $N_2$ and $H_2$.

Q. chemically unreactive three different gases A B and C of molecular masses 16, 32 and 64 are enclosed in a vessel at constant temperature till the equilibrium is reached which of the following statement is true
1)gas A will be at the top of vessel
2)gas​​​​​​ B will be at the top of vessel
3) gas C will be at the bottom of vessel
4) gases will form homogeneous mixture

Explain with proper reasoning

Q. When $31\text{g}$ of non-volatile solute is dissovled in $100\text{g}$ of water, the vapour pressure is lowered by $1.75\text{mm}$. If the vapour pressure of water at $25{}^o\text{C}$ is $17.5\text{mm}$, what is the molecular mass of solute $\left(\text{in g}\right)$?
(Use $\frac{100}{18}=5.55$)

1. $75\text{g}$
2. $25\text{g}$
3. $50\text{g}$
4. $45\text{g}$

Q.

How is it possible to make reversible reaction irreversible?

Q.

A chemical reaction $X\rightleftharpoons Y$ is said to be in equilibrium when -

1. 50% of the conversion has taken place

2. only 10% conversion of X to Y has taken place

3. the rate of transformation of X to Y is equal to the rate of transformation of Y to X in the system

4. there is change in the concentration of either x or y