Dalton's Law of Partial Pressures

Q.

Sulphur dioxide and oxygen react according to the equation :- $2S{O}_2\left(g\right)+O_2\left(g\right)\to 2S{O}_3\left(g\right)$.If 50.0 g of $S{O}_2$(g) is added to a flask resulting in a pressure of 0.750 atm.What will be the total pressure in the flask when a stochiometric amount of oxygen is added?What is the pressure after the completion of reaction and before the beginning of the reaction (with $O_2$ just added)?

1. Before reaction = 1.125 atm , After reaction = 0.725 atm

2. Before reaction = 2.50 atm , After reaction = 1.000 atm

3. Before reaction = 1.125 atm , After reaction = 0.750 atm

4. Before reaction = 2.50 atm , After reaction = 1.125 atm

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. If a given quantity of PCl5 is heated to 250 degree celsius and allowed to come to equilibrium at atmospheric pressure it is found to be dissociated to the extent of 80% into PCl3 and chlorine. If now, the pressure on this mixture is increased so that finally the equilibrium mixture occupies only one half of its original volume ( temperature maintained constant).i) What will the % dissociation at the new pressure?ii) What will be the effect of adding He gas keeping the volume fixed at V/2?

Q. A mixture of two gases A and B in themole ratio 2 : 3 is kept in a 2 litre vessel. Asecond 3L vessel has the same twogases in the mole ratio 3 5. Both gasmixtures have the same temperature andsame total pressure. They are allowed tointer-mix and the final temperature andthe total pressure are the same as theinitial values, the final volume being 5litres. Given that the molar masses areMA and MB. What is the mean molarmass of the final mixture?

Q.

The total pressure of a mixture of 6.4 grams of oxygen and 5.6 grams of nitrogen present in a 2 lit vessel is 1200mm. What is the partial pressure of nitrogen in mm?

1. 200

2. 1200

3. 600

4. 900

Q.

Sulphur dioxide and oxygen react according to the equation :- $2S{O}_2\left(g\right)+O_2\left(g\right)\to 2S{O}_3\left(g\right)$.If 50.0 g of $S{O}_2$(g) is added to a flask resulting in a pressure of 0.750 atm.What will be the total pressure in the flask when a stochiometric amount of oxygen is added?What is the pressure after the completion of reaction and before the beginning of the reaction (with $O_2$ just added)?

1. Before reaction = 1.125 atm , After reaction = 0.725 atm

2. Before reaction = 2.50 atm , After reaction = 1.000 atm

3. Before reaction = 1.125 atm , After reaction = 0.750 atm

4. Before reaction = 2.50 atm , After reaction = 1.125 atm

Q.

3g of $H_2$ and 24g of $O_2$ are present in a gaseous mixture at constant temperature and pressure. Find the partial pressure of hydrogen.

1. $\frac{1}{3}$ of total pressure

2. $\frac{2}{3}$ of total pressure

3. $\frac{3}{2}$ of total pressure

4. $\frac{1}{2}$ of total pressure

Q.

$2500{\mathrm{cm}}^3$ of hydrogen is taken at S.T.P. The pressure of this gas is further increased by two and a half times (temperature remaining constant). What volume did hydrogen occupy now?

Q. The degree of dissociation of I2(iodine gas) molecule of 1000^°C and under atmospheric pressure is 40% by volume. If dissociation is reduced to 20% at the same temperature, total equilibrium pressure on the gas is (a) 1.57 atm (b) 2.57 atm (c)3.57 (d) 4.57 atm

Q.

A vessel contains 0.16g of methane and 0.28g of nitrogen. The ratio of partial pressures of methane to nitrogen in the mixture is about:

1. 1 : 1

2. 2 : 3

3. 4 : 7

4. 7 : 4

Q.

One mole of $N_{2}and3$ moles of $PC{l}_5$ are placed in a 100 litre vessel heated to ${227}^{\circ }C$. The equilibrium pressure is 2.05 atm. Assuming ideal behaviour, calculate degree of dissociation of $PC{l}_5$ for the reaction $PC{l}_5\rightleftharpoons PC{l}_3+C{l}_2$.

1. 66.6 %

2. 25 %

3. 33.3 %

4. 10 %

Q.

$n_1$ and $n_2$ moles of two ideal gases (mol. wt. $M_1$ and $M_2$) respectively at temperature $T_1$K and $T_2$K are mixed. Assuming that no loss of energy, the temperature of mixture becomes

1. 

2. 

3. 

4. 

Q. Dinitrogen and dihydrogen react with each other to produce ammonia according to the following chemical equation:

Q. A $1:1$ mixture (by weight) of hydrogen and helium is enclosed in a one-litre flask at $0{}^{\circ }\text{C}$. Assuming ideal behaviour, the partial pressure of helium is found to be $0.42atm$, then the concentration of hydrogen would be:

1. $0.0375$ M
2. $0.028$ M
3. $0.0562$ M
4. $0.0187$ M

Q. The partial pressure of hydrogen in a flask containing $2g$ of hydrogen and $32g$ of sulphur dioxide is:

1. $1/{16}^{th}$ of the total pressure
2. $1/9^{th}$ of the total pressure
3. $2/3^{rd}$ of the total pressure
4. $1/8^{th}$ of the total pressure

Q. Consider the following statements.

(I) At constant temperature, density of a fixed mass of the gas is directly proportional to the pressure

(II) The lowest hypothetical temperature at which gases are supposed to occupy zero volume is called absolute zero.

(III) Pressure exerted by saturated water vapour is called aqueous tension.

The correct statement(s) among the following is/are

निम्नलिखित कथनों पर विचार कीजिए।

(I) नियत ताप पर, निश्चित द्रव्यमान वाली गैस का घनत्व दाब के समानुपाती होता है।

(II) वह न्यूनतम काल्पनिक ताप जिस पर गैसें शून्य आयतन ग्रहण करती हैं, परम शून्य कहलाता है।

(III) संतृप्त जल वाष्प द्वारा डाला गया दाब जलीय तनाव कहलाता है।

निम्नलिखित में से सही कथन है/हैं

1. I only
   
   केवल I
2. I and II only
   
   केवल I एवं II
3. II and III only
   
   केवल II एवं III
4. I, II and III
   
   I, II एवं III

Q.

$n_1$ and $n_2$ moles of two ideal gases (mol. wt. $M_1$ and $M_2$) respectively at temperature $T_1$K and $T_2$K are mixed. Assuming that no loss of energy, the temperature of mixture becomes -

1. $n_1{T}_1+n_2{T}_2$

2. $\frac{n_1{T}_1+n_2{T}_2}{T_1+T_2}$

3. $\frac{n_1{T}_1+n_2{T}_2}{n_1+n_2}$

4. $\frac{n_1\times T_2}{n_1\times n_2}$

Q. Assume that you have a sample of a gas containing $H_2,HD$ and $D_2$ that you want to separate into pure components $(H={}^{1}H\text{and}D={}^{2}H)$. What are the relative rates of diffusion of the three gases according to Graham’s law?

1. $H_2>HD>D_2$
2. $D_2>HD>H_2$
3. $D_2>H_2>HD$
4. All have same rate

Q.

$N_2$ is found in a litre flask under 100kPa pressure and $O_2$ is found in another 3 litre flask under 320 kPa pressure. If the two flasks are connected, the resultant pressures is

1. 310 kPa

2. 210 kPa

3. 420 kPa

4. 365 kPa

5. 265 kPa

Q. 1 litre of mixture of $CO$ and $C{O}_2$is taken. The mixture is passed through a tube containing red hot charcoal. The volume now becomes 1.6 litre. The volumes are measured under the same conditions. The volume of $C{O}_2$ in the original mixture is

Q. 8. The partial pressure of hydrogen incontaining 2 g H, and 32 g 50, isFask(1)1/16th of toal pressure1/9th of total pressure(2)(3) 2/3rd of total pressure1/8th of total pressure(4)

Q. A vessel is filled with a mixture of oxygen and nitrogen. At what ratio of partial pressure will the mass of the gases be identical?

1. $p\left(O_2\right)=0.785p\left(N_2\right)$
2. $p\left(O_2\right)=8.75p\left(N_2\right)$
3. $p\left(O_2\right)=11.4p\left(N_2\right)$
4. $p\left(O_2\right)=0.875p\left(N_2\right)$

Q.

A mixture containing 1.6 g of $O_2$, 1.4 g of $N_2$ and 0.4 g of $He$ occupies a volume of $10L$ at ${27}^{\circ }C$. Calculate the partial pressure of each component of the mixture.

1. $P_{N_2}=0.500atm$
   $P_{O_2}=0.25atm$
   $P_{He}=0.25atm$
   
   

2. $P_{N_2}=0.246atm$
   $P_{O_2}=0.246atm$
   $P_{He}=0.492atm$
   
   

3. $P_{N_2}=0.123atm$
   $P_{O_2}=0.123atm$
   $P_{He}=0.246atm$

4. $P_{N_2}=1atm$
   $P_{O_2}=1.123atm$
   $P_{He}=2.246atm$
   

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.

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.

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

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. 30

2. 32

3. 28

4. 16

Q. Assertion :Propane can be decomposed chemically Reason: Propane is a compound that is made up of simpler elements

1. Both Assertion and Reason are correct and Reason is the correct explanation for Assertion
2. Both Assertion and Reason are correct but Reason is not the correct explanation for Assertion
3. Assertion is correct but Reason is incorrect
4. Both Assertion and Reason are incorrect

Q.

Sulphur dioxide and oxygen react according to the equation :- $2S{O}_2\left(g\right)+O_2\left(g\right)\to 2S{O}_3\left(g\right)$.If 50.0 g of $S{O}_2$(g) is added to a flask resulting in a pressure of 0.750 atm.What will be the total pressure in the flask when a stochiometric amount of oxygen is added?What is the pressure after the completion of reaction and before the beginning of the reaction (with $O_2$ just added)?

1. Before reaction = 1.125 atm , After reaction = 0.725 atm

2. Before reaction = 2.50 atm , After reaction = 1.000 atm

3. Before reaction = 1.125 atm , After reaction = 0.750 atm

4. Before reaction = 2.50 atm , After reaction = 1.125 atm

Q. What will be the ratio of partial pressures of $10$ moles of $He$ and $5$ moles of $C{H}_4$ present in a reaction mixture?

1. $1:2$
2. $2:1$
3. $1:3$
4. $3:1$