# Graham's Law of Effusion

## Trending Questions

**Q.**Choose the correct option for the total pressure (in atm.) in a mixture of 4 g O2 and 2 g H2 confined in a total volume of one litre at 0°C is:

Given,

R=0.082 L.atm mol–1K–1T=273K

- 2.602
- 25.18
- 26.02
- 2.518

**Q.**CO2 gas is bubbled through water during a soft drink manufacturing process at 298 K. If CO2 exerts a partial pressure 0.835 bar them x mmol of CO2 would dissolve in 0.9 L water. The value of x is (Nearest integer)

(Henry's law constant for CO2 at 298 K is 1.67×103 bar)

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

- HCl and He atoms
- SiF4 and He atoms
- H2O and alcohols
- Cl2 and CCl4

**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 49 u. Molecular mass of B will be:

- 50.00 u
- 12.25 u
- 6.50 u
- 25.00 u

**Q.**A vessel contains H2 and O2 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 H2 to that of O2 coming out through the hole.

- 1 : 8
- 32 : 1
- 1 : 32
- 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........

64 min

12 min

32 min

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

- 0.25
- 0.5
- 1.5
- 1/24

**Q.**X ml of H2 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:

- 20 seconds: O2
- 25 seconds: CO
- 35 seconds: CO2
- 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 SO3. Hence, mole fraction of n-butane in LPG is

- 0.75
- 0.25
- 0.87
- 0.51

**Q.**Decomposition of both A2(g) and B3(g) follows 1st order kinetics as:

A2(g)k1−→2A(g) k1(hr−1)=102e−14000RT

B3(g)k2−→3B(g) k2(hr−1)=103e−20000RT

If 1 mol of A2(g) and B3(g) are taken in a 10 L 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 1.0 hr.

**Q.**Lysine has pKa1=2.18, pKa2=8.95, pKa3=10.53.

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

**Q.**What is the correct relationship between the pHs of isomolar solutions of sodium oxide (pH1), sodium sulphide (pH2), sodium selenide pH3) and sodium telluride pH4) ?

- pH1>pH2≈pH3>pH4
- pH1<pH2<pH3<pH4
- pH1<pH2<pH3≈pH4
- pH1>pH2>pH3>pH4

**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:

- Molar masses is 16 : 1
- Molar masses is 1 : 4
- Moles present inside the container is 1 : 24
- 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?

- Diprotium and dideuterium
- Dideuterium and helium
- Ethene and ethane
- 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 H2 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:

- 0.71
- 1.00
- 1.41
- 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 NH3 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:

- 118.9 cm
- 81.1 cm
- 150.1 cm
- 108.9 cm

**Q.**According to Graham's law, at a given temperature, the ratio of the rates of diffusion rArB of gases A and B is given by:

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

- (PAPB)(MAMB)12
- (MAMB)(PAPB)12
- (PAPB)(MBMA)12
- (MAMB)(PBPA)12

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

2A(g)→4B(g)+C(g)

- 0.8 min
- 0.4 min
- 1.4 min
- 2.5 min

**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

- √2π
- 2π
- √2π
- √π2

**Q.**180 mL of a hydrocarbon diffuses through a porous membrane in 15 minutes while 120 mL of SO2 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.

- He
- H2
- N2
- D2

**Q.**The reaction between gaseous NH3 and HBr produces a white solid NH4Br . Suppose a small quantity of gaseous NH3 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 NH3.

**Q.**The rate constants k1and k2 for two different reactions are 1016.e−2000/T and 1015.e−1000/T respectively, the temperature at which k1=k2, is:

- T=431.2K
- T=434.2K
- T=404.2K
- T=432.2K

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

- NH3
- H2O
- HCl
- 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

- π:1
- 1:π
- 1:1
- 3:2

**Q.**A vessel having volume of 8.21 L is found to contain 3 moles of CO2 and 2 moles of He. What is the partial pressure of He in the vessel at 400 K?

- 2.4 atm
- 8 atm
- 12 atm
- 4.8 atm

**Q.**

Helium gas at 1 atm and SO2 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 SO2 would traverse in the same time interval in the other tube ?

25 cm

50 cm

60 cm

75 cm

**Q.**

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

**Q.**The rate of effusion of LPG (a mixture of n-butane and propane) is 1.25 times that of SO3. Hence, mole fraction of n-butane in LPG is

- 0.5
- 0.25
- 0.75