S3 Chem: Kinetic Particle Theory

The boiling points of some substances are given in the table.

A mixture of these three substances is warmed from room temperature to 75 ^oC. What will happen?

• Pentane will remain a liquid.

• Decane will remain a liquid.

• Pentane and hexane will remain liquids.

• Pentane, hexane and decane will be gases.

The diagram represents a change in the structural arrangement of particles in two different physical states.

Which of the following statements will always be true?

• The particles get more orderly.

• The particles lose energy to the surroundings.

• The temperature of the surrounding rises due to structural change.

• The particles gain energy from the surroundings.

The graph shows the heating curve of a substance. The substance started as a solid, melted to become a liquid, which boiled to become a vapour.

From the graph, at which temperature does both liquid and gas exist together?

• 25 ^oC

• 50 ^oC

• 75 ^oC

• 125 ^oC

Balloons are usually made of latex, which is a porous material that allows gas molecules to move in and out.

An inflated balloon when placed in liquid nitrogen (melting point: -210 ^oC, boiling point: -196 ^oC), deflates quickly, and when it is removed, inflates again quickly.

 

Which of the following best explains this observation?

• The air particles move out of the balloon very quickly.

• The air particles contract when there is a decrease in temperature.

• A decrease in temperature reduces the attractive forces of the air particles.

• A decrease in temperature decreases the kinetic energy of the air particles.

Titan is the largest moon of the planet Saturn and is the only moon in the solar system with an atmosphere.

 

The substances in the table are present on the surface and/or in the atmosphere.

What would the rain on Titan mainly consist of at -185 ^oC?

• liquid argon

• liquid hydrogen

• liquid methane

• liquid nitrogen

Which changes occur when solid iodine sublimes?

• A

• B

• C

• D

A sample of liquid was allowed to cool until it completely became solid. The graph shows how the temperature of the sample changes with time.

Between which points on the graph was the sample in both liquid and solid state during cooling?

• P to Q

• P to Q and R to S

• Q to R

• R to S

The diagram shows the arrangement of molecules of a substance at two different temperatures.

Which substance could the diagram represent?

• A

• B

• C

• D

The sun-lit side of the planet Mercury has a temperature of 427 ^oC. The night side of the planet has a temperature of -180 ^oC.

 

Which substance may be found on one side of Mercury as a liquid and on the other side as a solid?

• A

• B

• C

• D

Which of the statement(s) is/are true?

• III only

• I and II only

• I and III only

• I, II and IV only