Dalton's Law of Partial Pressures

Q.

A sample of air contains nitrogen, oxygen and saturated with water vapour under a total pressure of 640 mm. If the vapour pressure of water at that temperature is 40 mm and the molecular ratio of $N_2:O_2$ is 3 : 1. Find the partial pressure of nitrogen in the sample.

1. 480 mm

2. 600 mm

3. 450 mm

4. 160 mm

Q. Gaseous Benzene reacts with hydrogen gas in presence of a Nickel catalyst to form gaseous cyclohexane according to the Reaction

$C_6{H}_6+3H_2⟶C_6{H}_{12}$

A mixture of $C_6{H}_6$ and excess $H_2$ has a pressure of 60mm of Hg in an unknown volume. After the gas had been passed over a Ni catalyst and all the benzene converted to cyclohexane, the pressure of the gas was 30mm of Hg in the same volume at the same temperature. The fraction of $C_6{H}_6$ (by volume) present in the original volume is

1. 1/3

2. 1/4

3. 1/5

4. 1/6

Q.

Find total pressure observed after opening the stopcock . [neglecting the volume of the tube connecting the two bulbs]

1. 1.33 atm

2. 3 atm

3. 0.3 atm

4. 0.75 atm

Q. 0.157 g of a certain gas collected over water occupied a volume of 135 ml at ${27}^{0}C$ and 750 mm of Hg. Assuming ideal behaviour, the molecular weight of the gas is (aqueous tension at ${27}^{0}C$ is 26.7 mm of Hg)

1. 28

2. 32

3. 16

4. 30

Q.

Dalton’s law of partial pressure is not applicable to a mixture of

1. 

2. 

3. 

4. 

Q. What is the density of wet air (in $\text{g/L}$) that has the partial pressure of water of $22.5$ torr at $1$ atm and $300\text{K}$?
$($Given: vapour pressure of $H_{2}O$ is $30$ torr and the average molar mass of air is $29\text{g/mol})$

1. $1.164\text{g/L}$
2. $4.164\text{g/L}$
3. $2.164\text{g/L}$
4. $3.164\text{g/L}$

Q.

A mixture of hydrogen and oxygen at one bar pressure contains 20% by weight of hydrogen. Find the partial pressure of hydrogen.

1. 0.2 bar

2. 0.4 bar

3. 0.6 bar

4. 0.8 bar

Q.

A sample of $O_2$ gas is collected over water at ${23}^{\circ }$ C at a barometric pressure of 751 mm Hg (vapour pressure of water at ${23}^{\circ }$ C is 21 mm Hg). The partial pressure of $O_2$ gas in the sample collected is ......

1. 21 mm Hg

2. 751 mm Hg

3. 0.96 atm

4. 1.02 atm

Q.

If a mixture of $C{O}_{2}and{N}_2$ in equal amount exert a total pressure of 1 atm, the partial pressure of $N_2$ in the mixture is –

1. 1.52 atm

2. 0.56 atm

3. 1 atm

4. 0.75 atm

Q.

A gaseous mixture of three gases A, B and C has a pressure of 10atm. The total number of moles of all gases is 10. The partial pressure of A and B are 3 and 1 atm respectively. If C has a molecular weight of 2, then find the weight of C in grams present in the mixture.

1. 6

2. 3

3. 12

4. 8