Revision EOT1

The diagrams show four pieces of laboratory equipment.

• A

• B

• C

• D

A student carried out paper chromatography on a mixture of amino acids. The student sprayed the dried chromatogram with a locating agent. What is the function of the locating agent?

• to dissolve the amino acids

• to form coloured spots with the amino acids

• to preserve the amino acids

• to stop the amino acids reacting

25 cm³ of an alkali are added to 20 cm³ of an acid. The temperature change is measured. Which apparatus is not needed in the experiment?

• 25 cm³ measuring cylinder

• 100 cm³ beaker

• balance

• thermometer

The painkiller paracetamol is synthesised from 4-aminophenol. Chromatography was carried out on an impure sample of paracetamol. The results are shown (not drawn to scale).

The sample of paracetamol was contaminated with 4-aminophenol only. What is the R_f value of 4-aminophenol?

• 0.49

• 0.65

• 0.74

• 1.35

A student put 25.0 cm³ of dilute hydrochloric acid into a conical flask. The student added 2.5 g of solid sodium carbonate and measured the change in temperature of the mixture. Which apparatus does the student need to use to obtain the most accurate results?

• balance, measuring cylinder, thermometer

• balance, pipette, stopwatch

• balance, pipette, thermometer

• burette, pipette, thermometer

A solid X is purified in five steps. The first four steps of the purification are shown in the diagram.

In step 5, how is a pure sample of solid X obtained from mixture Y?

• dissolving

• distillation

• evaporating

• filtering

Substance L melts at –7°C and is a brown liquid at room temperature. Which temperature is the boiling point of pure L?

• –77 °C

• –7 °C to +7 °C

• 59 °C

• 107 °C to 117 °C

Large hydrocarbons can be .….X….. to make smaller, more useful molecules. Small molecules can be …..Y….. to make long molecules.

What are X and Y?

• A

• B

• C

• D

An ice cube is gently warmed as shown. Which process is taking place?

• Decomposition

• Dissolving

• Boiling

• Melting

A solid has a giant structure. It does not conduct electricity but does so when it is dissolved in water. What could the solid be?

• A

• B

• C

• D