Graham's Law of Effusion

Q. Choose the correct option for the total pressure (in atm.) in a mixture of $4g$ $O_2$ and $2g$ $H_2$ confined in a total volume of one litre at $0°C$ is:
Given,
$R=0.082L.atmmo{l}^{–1}{K}^{–1}T=273K$

1. 2.602
2. 25.18
3. 26.02
4. 2.518

Q. $C{O}_2$ gas is bubbled through water during a soft drink manufacturing process at $298K$. If $C{O}_2$ exerts a partial pressure $0.835$ bar them $x$ $\text{mmol}$ of $C{O}_2$ would dissolve in $0.9L$ water. The value of $x$ is (Nearest integer)
(Henry's law constant for $C{O}_2$ at $298K$ is $1.67\times {10}^3$ bar)

Q. Dipole-induced dipole interactions are present in which of the following pairs?

1. $HCl$ and $He$ atoms
2. $Si{F}_4$ and $He$ atoms
3. $H_{2}O$ and alcohols
4. $C{l}_2$ and $CC{l}_4$

Q. Two gases $A$ and $B$ having the same volume diffuse through a porous partition in $20$ and $10$ seconds respectively. The molecular mass of $A$ is $49u$. Molecular mass of $B$ will be:

1. $50.00u$
2. $12.25u$
3. $6.50u$
4. $25.00u$

Q. A vessel contains $H_2$ and $O_2$ in the molar ratio of 8 : 1. This mixture of gases is allowed to diffuse through a hole. Find the ratio of the composition of $H_2$ to that of $O_2$ coming out through the hole.

1. 1 : 8
2. 32 : 1
3. 1 : 32
4. 8 : 1

Q.

50 ml of hydrogen diffuses out through a small hole from a vessel in 20 minutes. The time needed for 40 ml of oxygen to diffuse out is........

1. 64 min

2. 12 min

3. 32 min

4. 8 min

Q.

The ratio of rates of diffusion of gases A and B is 1 : 4. If the ratio of their masses present in the initial mixture is 2 : 3. The ratio of their mole fractions will be

1. 0.25
2. 0.5
3. 1.5
4. 1/24

Q. $X\text{ml}$ of $H_2$ gas effuses through a hole in a container in 5 seconds. The time taken for the effusion of the same volume of the gas specified below under identical condition is:

1. 20 seconds: $O_2$
2. 25 seconds: $CO$
3. 35 seconds: $C{O}_2$
4. 10 seconds: $He$

Q. 50 mL of hydrogen takes 20 minutes to diffuse out of a vessel. How long ( in minutes) will 40 mL of oxygen take to diffuse out from the same vessel under the same conditions?

Q. Rate of diffusion of LPG (mixture of n-butane and propane) is 1.25 times faster than that of $S{O}_3$. Hence, mole fraction of n-butane in LPG is

1. 0.75
2. 0.25
3. 0.87
4. 0.51

Q. Decomposition of both $A_2\left(g\right)$ and $B_3\left(g\right)$ follows $1^{st}$ order kinetics as:
$A_2\left(g\right)\stackrel{k_1}{\to }2A\left(g\right)k_1\left(h{r}^{-1}\right)={10}^2{e}^{-\frac{14000}{RT}}$
$B_3\left(g\right)\stackrel{k_2}{\to }3B\left(g\right)k_2\left(h{r}^{-1}\right)={10}^3{e}^{-\frac{20000}{RT}}$
If $1mol$ of $A_2\left(g\right)$ and $B_3\left(g\right)$ are taken in a $10L$ evacuated flask and heated to some temperature so that they start decomposing at the same rate, determine total pressure (in $atm$) in the flask after $1.0hr$.

Q. $\text{Lysine has}p{K}_{a_1}=2.18,p{K}_{a_2}=8.95,p{K}_{a_3}=10.53$.

In which structure lysine will be present at $pH=9.7$.

1. 
2. 
3. 
4. 

Q. What is the correct relationship between the pHs of isomolar solutions of sodium oxide $\left(p{H}_1\right),$ sodium sulphide $\left(p{H}_2\right),$ sodium selenide $p{H}_3)$ and sodium telluride $p{H}_4)$ ?

1. $p{H}_1>p{H}_2\approx p{H}_3>p{H}_4$
2. $p{H}_1<p{H}_2<p{H}_3<p{H}_4$
3. $p{H}_1<p{H}_2<p{H}_3\approx p{H}_4$
4. $p{H}_1>p{H}_2>p{H}_3>p{H}_4$

Q. The rate of diffusion of two gases 'A' and 'B' are in the ratio 16 : 3. If the ratio of their masses present in the mixture is 2 : 3, then the ratio of their:

1. Molar masses is 16 : 1
2. Molar masses is 1 : 4
3. Moles present inside the container is 1 : 24
4. Moles present inside the container is 8 : 3

Q. Which of the following pairs of gases will have identical rate of effusion under similar conditions?

1. Diprotium and dideuterium
2. Dideuterium and helium
3. Ethene and ethane
4. Carbon dioxide and ethane

Q. Consider a tube that has a frilled disk sealed in its centre so that gases can effuse through it in both directions. If the left hand side contains $H_2$ at a pressure $P$ and temperature $T$ and the right hand side contains $He$ at a pressure $2P$ and temperature $T$, then initial ratio of effusion is:

1. $0.71$
2. $1.00$
3. $1.41$
4. $0.50$

Q. A straight glass tube has 2 inlets $X$ and $Y$ at the two ends of a 200 cm long tube as shown in the figure. $HCl$ gas through inlet $X$ and $N{H}_3$ gas through inlet $Y$ are allowed to enter in the tube at the same time and under identical conditions. At a point $P$ inside the tube, both the gases meet first. The distance of point $P$ from $X$ is:

1. 118.9 cm
2. 81.1 cm
3. 150.1 cm
4. 108.9 cm

Q. According to Graham's law, at a given temperature, the ratio of the rates of diffusion $\frac{r_A}{r_B}$ of gases $A$ and $B$ is given by:

(where $P$ and $M$ are pressures and molecular weights of gases $A$ and $B$ respectively)

1. $\left(\frac{P_A}{P_B}\right){\left(\frac{M_A}{M_B}\right)}^{\frac{1}{2}}$
2. $\left(\frac{M_A}{M_B}\right){\left(\frac{P_A}{P_B}\right)}^{\frac{1}{2}}$
3. $\left(\frac{P_A}{P_B}\right){\left(\frac{M_B}{M_A}\right)}^{\frac{1}{2}}$
4. $\left(\frac{M_A}{M_B}\right){\left(\frac{P_B}{P_A}\right)}^{\frac{1}{2}}$

Q. The reaction given below, is observed to be a first order with rate constant $7.5\times {10}^{-3}{s}^{-1}$. Calculate the time required for the total pressure in a system containing A at an initial pressure of $0.1atm$ to rise to $0.145atm$.

$2A\left(g\right)\to 4B\left(g\right)+C\left(g\right)$

1. $0.8min$
2. $0.4min$
3. $1.4min$
4. $2.5min$

Q. Two gases $A$ and $B$ present seperately in two vessels $X$ and $Y$ at the same temperature with molecular weights $M$ and $2M$ respectively are effused out. The orifice in vessel $X$ is circular while that in $Y$ is a square. If the radius of the circular orifice is equal to that of the length of the square orifice, the ratio of effusion of gas $A$ to that of gas $B$ is

1. $\sqrt{2}\pi$
2. $2\pi$
3. $\sqrt{\frac{2}{\pi }}$
4. $\sqrt{\frac{\pi }{2}}$

Q. $180\text{mL}$ of a hydrocarbon diffuses through a porous membrane in 15 minutes while $120\text{mL}$ of $S{O}_2$ under identical conditions diffuses in 20 minutes. What is the molecular mass of the hydrocarbon?

Q. Under similar conditions which of the following gases will diffuse four times as fast as oxygen.

1. $He$
2. $H_2$
3. $N_2$
4. $D_2$

Q. The reaction between gaseous $N{H}_3$ and $HBr$ produces a white solid $N{H}_{4}Br$. Suppose a small quantity of gaseous $N{H}_3$ and gaseous $HBr$ are introduced simultaneously into opposite ends of an open tube which is one metre long. Calculate the distance of white solid formed from the end which was used to introduce $N{H}_3$.

Q. The rate constants $k_1$and $k_2$ for two different reactions are ${10}^{16}.e^{-2000/T}$ and ${10}^{15}.e^{-1000/T}$ respectively, the temperature at which $k_1=k_2$, is:

1. $T=431.2K$
   
2. $T=434.2K$
3. $T=404.2K$
4. $T=432.2K$

Q. Which of the following exhibits the weakest inter-molecular forces?

1. $N{H}_3$
2. $H_{2}O$
3. $HCl$
4. $He$

Q. A certain gas effuses out of two different vessels $A$ and $B$. $A$ has a circular orifice while $B$ has a square orifice of length equal to the radius of the orifice of vessel $A$. The ratio of rate of diffusion of the gas from vessel $A$ to that from vessel $B$ is

1. $\pi :1$
2. $1:\pi$
3. $1:1$
4. $3:2$

Q. A vessel having volume of $8.21\text{L}$ is found to contain $3$ moles of $C{O}_2$ and $2$ moles of $He$. What is the partial pressure of $He$ in the vessel at $400\text{K}$?

1. $2.4\text{atm}$
2. $8\text{atm}$
3. $12\text{atm}$
4. $4.8\text{atm}$

Q.

Helium gas at 1 atm and $S{O}_2$ at 2 atm pressure, temperature being the same, are released seprately at the same moment into 1m long evacuated tubes of equal diameters. If helium reaches the other end of the tube in ts, what distance $S{O}_2$ would traverse in the same time interval in the other tube ?

1. 25 cm

2. 50 cm

3. 60 cm

4. 75 cm

Q.

For CO, isotherm is of the type as shown.Near the pointA , compressibility factor Z is

1. 

2. 

3. 

4. 

Q. The rate of effusion of LPG (a mixture of n-butane and propane) is 1.25 times that of $S{O}_3$. Hence, mole fraction of n-butane in LPG is .

1. 0.5
2. 0.25
3. 0.75