Chemistry

Which row about a change of state is correct?

• A

• B

• C

• D

A gas is released at point P in the apparatus shown. Which gas turns the damp universal indicator paper red most quickly?

• Water

• Hydrochloric acid

• Sugar solution

• Ammonia

Gases are separated from liquid air by fractional distillation. The boiling points of four gases are shown. Which TWO gaseous are liquid at –200 °C?

• A

• B

• C

• D

The chromatogram of substance S is shown. Some distances, W, X, Y and Z, are labelled on the diagram. How is the R_f value of substance S calculated?

• A

• B

• C

• D

In the chromatography experiment shown, which label represents the solvent front?

• A

• B

• C

• D

Which one of the four dyes is an impure substance?

• A

• B

• C

• D

What is the physical state of compound X in the region CD?

A mixture of ethanol and methanol is separated by fractional distillation. This method of separation depends on a difference in property X of these two alcohols. What is property X?

• Boiling point

• Solubility

• Colour

• Melting point

Which change of state takes place during evaporation?

• Solid to gas

• Gas to liquid

• Liquid to gas

• Liquid to solid

‘Particles moving very slowly from an area of high concentration to an area of low concentration.’ Which process is being described above?

• a liquid being frozen

• a solid melting

• a substance diffusing through a liquid

• a substance diffusing through the air