Pure Substances and Mixtures

Which of the following is the correct reason why crystallisation is used to obtain sugar from sugar solution, instead of evaporation?

• Evaporation forms impure sugar.

• Sugar is a compound and not a mixture.

• Sugar decomposes on heating.

• Evaporation takes a longer time.

Which process could purify the muddy water as shown?

• Crystallisation

• Filtration

• Distillation

• Solvent extraction

Which separation method uses this set of apparatus?

• Simple distillation

• Fractional distillation

• Separating funnel

• Chromatography

Which of the following is the example of heterogeneous mixture?

• Water

• Muddy water

• Tea

• Vinegar

What is the boiling point of salt solution (mixed with water)?

• 104 C

• 100 C

• 0 C

• -5 C

A sample of water has the boiling point of 110 C and melting point of -8 C. Is the sample pure?

• Yes

• No

Which methods can be used to separate salt from its solution?

• Filtration and evaporation to dryness

• Sublimation and using magnet

• Crystallisation and evaporation to dryness

• Evaporation to dryness and decanting

Which one is the correct order in crystallisation?

1. Heat the solution until it is saturated

2. Rinse and dry the crystal

3. Filter the crystal

4. Cool it down

• 1-4-3-2

• 4-1-3-2

• 3-2-1-4

• 2-1-4-3

The liquid that can passes through the filtration is called ...

The presence of ... is intended to maintain even boiling with not too much bumping in distillation.