# Graham's Law of Effusion

## Trending Questions

**Q.**

The ratio of root mean square velocity to average velocity of gas molecules at a particular temperature is

1.086 : 2

1.086 : 1

1 : 1.086

2 : 1.086

**Q.**

2 grams of Helium diffuses from a porous plate in 4min. How many grams of CH4 would diffuse through the same plate in same time under similar conditions?

4g

16g

8g

2g

**Q.**

If some moles of O2 diffuse in 18 sec and same moles of other gas diffuse in 45 sec then what is the molecular weight of the unknown gas

**Q.**

If the rate of diffusion of $A$ is $5times$ that of $B$, what will be the density ratio of $A$ and $B$?

$\frac{1}{5}$

$5$

$25$

$\frac{1}{25}$

**Q.**

See the figure

The valves of X and Y are opened simultaneously.

The white fumes of NH4Cl will first form close to which of A, B and C?

A

B

A, B and C simultaneously

C

**Q.**

Under the same conditions, the rates of diffusion of two gases are in the ratio 1 : 4. The ratio of their vapour densities is ___.

2 : 1

1 : 2

16 : 1

1 : 16

**Q.**Equal mass of SO2 and CH4 are introduced in two different vessels - SO2 in a 4 litre vessel and CH4 in a 2 litre vessel at the same temperature. Both vessels have identical pin holes. What is the ratio of the rates of diffusion of SO2 and CH4, if the rate is calculated in mol/s?

- 1:2
- 1:8
- 1:16
- 1:4

**Q.**

The ratio fo rates of diffusion of SO2, O2 and CH4 is

1 : √2 : 2

1 : 2 : 4

2 : √2 : 1

1 : 2 : √2

**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 rate of effusion is:

- 0.71
- 1.00
- 1.41
- 0.50

**Q.**

50 mL of H2 gas diffuses through a small hole from a vessel in 20 min. Time taken by 40 mL of O2 gas to diffuse under similar conditions will be :

12 min

64 min

8 min

32 min

**Q.**1 mol of helium and 3 mol of N2 exert a pressure of 16 atm. Due to a hole in the vessel in which the mixture is placed, the mixture leaks out. Thus, the ratio of rates of helium and nitrogen effusing out initially is:

- 1.14
- 0.38
- 2.65
- 0.88

**Q.**

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

0.75

0.25

0.67

0.50

**Q.**

The ratio fo rates of diffusion of SO2, O2 and CH4 is

1 : √2 : 2

1 : 2 : 4

2 : √2 : 1

1 : 2 : √2

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

- He
- N2
- H2
- D2

**Q.**

If methane and helium are allowed to diffuse out of a container under identical conditions of temperature and pressure, the ratio of rate of diffusion of methane to helium is:

4.0

2.0

1.0

0.5

**Q.**A straight glass tube as shown has 2 inlets X and Y at the two ends of 200 cm long tube. HCl gas through inlet X and NH3 gas through inlet Y are allowd to enter in the tube at the same time and under the 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
- 91.1 cm
- 108.9 cm

**Q.**

If some moles of O2 diffuses in 18 sec and same moles of other gas diffuses in 45 sec.Find the molecular weight of the unknown gas .

**Q.**

The ratio of the rate of diffusion of helium and methane under identical condition of pressure and temperature will be___.

4

2

1

0.5

**Q.**

Find the value of |X+Y+Z|.

**Q.**There are 100 persons sitting at equal distances in a row XY. N2O gas (laughing gas) is released from the side X and tear gas (mol.mass = 176) from side Y at the same moment and at the same pressure. The person who will have a tendency to laugh and weep simultaneously is ?

- 34th from side X
- 67th from side X
- 76th from side X
- 67th from side Y

**Q.**The ratio of the rate of diffusion of helium and methane under the identical conditions of pressure and temperature will be:

- 4
- 2
- 1
- 0.5

**Q.**A certain volume of nitrogen gas at 0.8 atm takes 25 seconds to diffuse through a pin hole whereas the same volume of an unknown compound of xenon and flourine at 1.6 atm takes 37 second to diffuse through the same hole. The molecule formed can be expressed as XeFn. Find the value of n.

(Given: Molecular mass of Xe = 131 u)

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

- He
- H2
- N2
- D2

**Q.**20 dm3 of SO2 diffuses through a porous partition in 60 s. What volume (in dm3) of O2 will diffuse under similar conditions in 30 s?

**Q.**

It takes 26 s for 10 mL of H2 to effuse through a porous membrane. It takes 130 s for 10 mL of an unknown gas to effuse. Hence, molecular weight of the unknown gas is (in gmol−1 )

100

80

50

40

**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:

- 10 seconds: He
- 20 seconds: O2
- 25 seconds: CO
- 35 seconds: CO2

**Q.**X and Y are two volatile liquids with molar weights of 10 gmol−1and 40 gmol−1 respectively. Two cotton plugs, one soaked in X and the other soaked in Y, are simultaneously placed at the ends of a tube of length L = 24 cm, as shown in the figure. The tube is filled with an inert gas at 1 atmosphere pressure and a temperature of 300 K. Vapours of X and Y react to form a product which is first observed at a distance d cm from the plug soaked in X. Take X and Y to have equal molecular diameters and assume ideal behaviour for the inert gas and the two vapours.

The value of d in cm (shown in the figure as estimated from Graham’s law, is

- 8
- 12
- 16
- 20

**Q.**A bottle of dry ammonia and a bottle of dry hydrogen chloride connected with a long tube are opened simultaneously at both ends. The white ammonium chloride ring first formed will be:

- At the centre of the tube
- Near the hydrogen chloride bottle
- Near the ammonia bottle
- Throughout the length of the tube

**Q.**

See the figure

The valves of X and Y are opened simultaneously.

The white fumes of NH4Cl will first form close to which of A, B and C?

A

B

C

A, B and C simultaneously

**Q.**Equal mass of SO2 and CH4 are introduced in two different vessels - SO2 in a 4 litre vessel and CH4 in a 2 litre vessel at the same temperature. Both vessels have identical pin holes. What is the ratio of the rates of diffusion of SO2 and CH4, if the rate is calculated in mol/s?

- 1:2
- 1:8
- 1:16
- 1:4