Gases , MCQs related with gas chapter

 

Q. 1. Professor Qawwi told his students that air is a mixture because: suddenly a student raised his hand and said

a. it is colourless

b. oxygen can be removed from it

c. its composition is different at different altitudes

d. it has different properties from its constituents

(c)

 

Q. 2. Imagine Dr. Khan is sitting in a room. The room is closed from all sides, no entry, no exit of any gas. If the room expands suddenly then

a. he will be frightened

b. his blood pressure will decrease

c. he will feel cool

d. he will feel warmth

(c)

 

Q. 3. which of the following elements will have strongest Van Der Waal force of attraction between its molecules

a. hydrogen

b. oxygen

c. chlorine

d. nitrogen

(c)

 

Q. 4. The beaker shown in the figure contains slurry of ice and water, the three thermometers Fahrenheit, Kelvin and Centigrade placed in it. The thermometers are represented by A, B and C respectively. The lowest reading will be on thermometer.

a. A

b. B

c. C

d. Both A and C

(c)

 

Q. 5. Which thermometer will have its reading 273 degrees greater than that of thermometer C?

a. A

b. B

c. C has greater reading than all other thermometer

d. B has 273 degrees greater reading than A

(b)

 

Q. 6. The temperature recorded by Kelvin scale is

a. 0K

b. 273K

c. 373K

d. Absolute scale is unable to record this temperature

(b)

 

Q. 7. If three birds called O2, CI2 and H2 were flying in the garden of Islamia College Peshawar then,

I. Fastest birds are O2 and CI2

II. Slowest bird is CI2

III. Bird called O2 is in the middle.

a. I only

b. II and III only

c. I and III only

d. III only

(b)

 

Q. 8. One liter of an unknown gas weighs 1.25 grams at S.T.P, one possible formula for the gas is

a. CO2

b. CO

c. O2

d. SO2

(b)

 

Q. 9. If pressure on a gas is increased from 2 atm to 4 atm than its volume will decrease from

a. 6L to 4L

b. 8L to 2L

c. 3L to 1L

d. 4L to 2L

(d)

 

Q. 10. An unknown gas has a density of 2.45 g/L at 1.5 atmospheric pressure and 25 oC. The gas is

a. Kr

b. CI2

c. SO2

d. Ar

(d)

 

Q. 11. This is a known fact that the molar volumes of different gases at S.T.P are

a. little bit greater than the molar volumes of liquids

b. little bit less than the molar volumes of solids

c. about the same as the molar volumes of liquids

d. much larger than the molar volumes of liquids and solids

(d)

 

Q. 12. The behavior of a gas is non-ideal at

a. lo2w temperature and low pressure

b. high temperature and high pressure

c. high temperature and low pressure

d. low temperature and high pressure

(d)

Q. 13. Ammonium Perchlorate is used as solid fuel in rockets. During the process it decomposes according to the reaction given below

4NH4CIO4(g) 2CI2(g) +8H2O(g) +2N2O(g) +3O2(g)

The total volume of all the gases produced at S.T.P by the decomposition of 8 moles of

Ammonium Perchlorate will be

a. 30 L

b. 672 L

c. 179.0 L

d. 60 L

(b)

 

Q. 14. Compressed natural gas (CNG) contains mainly methane CH4. Methane gas burns in air according to the following reaction.

CH4(g) + 2O2(g) CO2(g) + 2H2O(g)

If 8 g of methane is burnt, what volume of CO2 measured at S.T.P. will be produced?

a. 0.5 L

b. 22 L

c. 22.4 L

d. 11.2 L

(d)

 

Q. 15. A kid has a helium filled balloon which deflates at the rate of 1.00 liter/day by He gas leaking through the relatively porous skin of the balloon. How fast would carbon dioxide (CO2) leak from a balloon made of the same material?

a. 3.0 L/day

b. 0.3 L/day

c. 1.33 L/day

d. 3.33 L/day

(b)

 

Q. 16. All of the following statements are false except

a. gas molecules do not attract each other at very low temperature

b. all of the gases cannot be liquefied

c. increase in pressure will not decrease the intermolecular distance in a gas

d. actual volume of a gas is not negligible at very high pressure

(d)

 

Q. 17. At the same temperature and pressure helium is more ideal than hydrogen due to

a. greater molar mass

b. less molar mass

c. greater molecular size

d. less molecular size

(d)

 

Q. 18. A container with a porous wall has a mixture of H2, He, N2 and O2. Which of these gases will take maximum time in getting out of the container?

a. H2

b. He

c. N2

d. O2

(d)

Q. 19. The value of R for an unknown gas is equal to

a. 0.082 L.atm.mol-1.K

b. 0.082 L.atm.mol-1.K-1

c. 0.82 L.atm.mol.K-1

d. 0.82 L.atm.mol.K

(b)

 

Q. 20. If the temperature of the atmosphere is 30oC then which of the following will have highest average speed

a. O2

b. H2

c. Ne

d. N2

(b)