Grade 9 Revision Questions MCQ

Samples of four gases are released in a room at the same time.

The gases are carbon dioxide, CO₂, hydrogen chloride, HCl, hydrogen sulfide, H₂S, and nitrogen dioxide, NO₂.

Which gas diffuses fastest?

• carbon dioxide

• hydrogen chloride

• hydrogen sulfide

• nitrogen dioxide

A student is asked to measure the time taken for 0.4 g of magnesium carbonate to react completely with 25.0 cm³ of dilute hydrochloric acid. Which pieces of apparatus does the student need?

• balance, stop-clock, pipette

• balance, stop-clock, thermometer

• balance, pipette, thermometer

• stop-clock, pipette, thermometer

Four different food colourings are analysed using chromatography. The results are shown on the chromatogram. The diagram is not drawn to scale. Which food colouring contains a component with an Rf value of 0.3?

• A

• B

• C

• D

Which statement about an ionic compound is not correct?

• It conducts electricity when dissolved in water.

• It has a high melting point due to strong attractive forces between ions.

• It has a regular lattice of oppositely charged ions in a ‘sea of electrons’.

• The ionic bonds are formed between metallic and non-metallic elements.

An isotope of chromium is represented by ⁵² Cr ₂₄ . Which statement about an atom of this isotope of chromium is correct?

• It contains 24 electrons.

• It contains 24 neutrons.

• It contains 28 protons.

• It contains 52 neutrons.

Element X has two isotopes, ¹²X₆ and ¹⁴X₆ .

Which statement about these isotopes is correct?

• They have different chemical properties because they have different numbers of neutrons.

• They have the same chemical properties because they have the same number of outer shell electrons.

• They have the same nucleon number because the sum of the number of protons and electrons is the same.

• They have different positions in the Periodic Table because they have different numbers of neutrons.

How are the structures of diamond and silicon(IV) oxide similar?

• Molecules of both diamond and silicon(IV) oxide are held together by weak attractive forces.

• They both contain atoms arranged in planes held together by weak bonds.

• They both contain ions that are free to move.

• The carbon in diamond and the silicon in silicon(IV) oxide each have four covalent bonds.

Which statement describes the structure of copper?

• It has a lattice of negative ions in a ‘sea of electrons’.

• It has a lattice of negative ions in a ‘sea of protons’.

• It has a lattice of positive ions in a ‘sea of electrons’.

• It has a lattice of positive ions in a ‘sea of protons’.

Four fertilisers are each supplied in 100 kg bags. Which fertiliser supplies the greatest mass of nitrogen per 100 kg bag?

• ammonium nitrate, NH₄NO₃

• ammonium phosphate, (NH₄)₃PO₄

• ammonium sulfate, (NH4)₂SO₄

• urea, CO(NH₂)₂

Calcium carbonate reacts with dilute hydrochloric acid. The equation for the reaction is shown.

CaCO₃ + 2HCl → CaCl₂ + H₂O + CO₂

1.00 g of calcium carbonate is added to 50.0 cm³ of 0.0500 mol/dm³ hydrochloric acid.

Which volume of carbon dioxide is made in this reaction?

• 30 cm³

• 60 cm³

• 120 cm³

• 240 cm³