Experimental Chemistry Quiz

Which apparatus would be most suitable for measuring 45.00 cm3 of sodium hydroxide?

• A beaker

• B burette

• C measuring cylinder

• D pipette

A student has a sample of colourless liquid. Which of the following properties is the best way to check the purity of the colourless liquid?

• A boiling point

• B density

• C melting point

• D no residue left when evaporated

Which of the following methods is used to separate a mixture of iodine and iron?

• A crystallisation

• B magnetic attraction

• C simple distillation

• D sublimation

Which of the following must be true in order for two substances to be separated by paper chromatography?

• A They have different colours.

• B They have different densities.

• C They have different boiling points.

• D They are soluble in the same solvent.

A gas can be collected using upward delivery and water displacement. Which of the following properties of this gas is correct?

• soluble in water & denser than air

• soluble in water & less dense than air

• insoluble in water & denser than air

• insoluble in water & less dense than air

You are given a mixture of hexane and a dilute solution of sodium chloride in water. Hexane boils at 69 oC and does not dissolve in water. To obtain samples of hexane and solid sodium chloride, which two techniques would you use?

• A distillation followed by filtration

• B evaporation to dryness followed by distillation

• C filtration followed by crystallisation

• D use a separating funnel followed by evaporation to dryness

Concentrated sulfuric acid is often used as a drying agent to obtain a dry sample of a moist gas. However, it is not suitable to dry a sample of ammonia gas. Why is this so?

• A Ammonia is soluble in water.

• B Ammonia is insoluble in water.

• C Ammonia will react with sulfuric acid.

• D The products formed will be too toxic.

Two groups of students conducted chromatography on the same sample of ink. The two chromatograms below show their results.

Why were their chromatograms different?

• A One group of students did not use enough sample.

• B One group of students did not use enough solvent.

• C The run time for the chromatograms were different.

• D The two groups of students used different solvents.

A gas sample contains a mixture of ammonia, carbon dioxide and methane. The properties of these gases are shown below. Order the steps needed to obtain a sample of methane from this gas mixture.

I pass the gas sample through water

II pass the gas sample through aqueous sodium hydroxide

III collect the gas using downward delivery

IV collect the gas by displacement of water

• I → III

• II → IV

• II → I → III

• I → II → IV

An experiment was carried out to separate a mixture T containing solids X, Y and Z. Solids X, Y and Z have the following properties. Which of the following correctly describes processes (i), (ii) and (iii)?

• (i) crystallisation

  (ii) filtration

  (iii) evaporation to dryness

• (i) crystallisation

  (ii) distillation

  (iii) crystallisation

• (i) sublimation

  (ii) distillation

  (iii) crystallisation

• (i) sublimation

  (ii) filtration

  (iii) evaporation to dryness