11 Chem Gases

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

• a. it is colorless
• b. oxygen can be removed from it
• c. its composition is different at different altitudes
• d. it has different properties from its constituents

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

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

• a. hydrogen
• b. oxygen
• c. chlorine
• d. nitrogen

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

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

• a. A
• b. B
• c. C has a greater reading than all other thermometers
• d. B has 273 degrees greater reading than A

Q. 6. The temperature recorded by the Kelvin scale is

• a. 0K
• b. 273K
• c. 373K
• d. Absolute scale is unable to record this temperature

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

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

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

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