Chemistry-qp21- M/J-2019 Quiz

2.00 g of powdered calcium carbonate is added to 50.0 cm³ of hydrochloric acid. Which apparatus is used to measure the calcium carbonate and the hydrochloric acid?

• A

• B

• C

• D

Which statement explains why ammonia gas, NH₃, diffuses at a faster rate than hydrogen chloride gas, HCl?

• Ammonia expands to occupy all of the space available.

• Ammonia has a smaller relative molecular mass than hydrogen chloride.

• Ammonia is an alkali and hydrogen chloride is an acid.

• Ammonia molecules diffuse in all directions at the same time.

The measurements from a chromatography experiment using substance F are shown. What is the Rf value of F?

• 0.55

• 0.61

• 0.90

• 1.64

Which statement about an atom of fluorine, ¹⁹₉F, is correct?

• It contains more protons than neutrons.

• It contains a total of 28 protons, neutrons and electrons.

• Its isotopes contain different numbers of protons.

• Its nucleus contains 9 neutrons.

Which row describes the formation of single covalent bonds in methane?

• A

• B

• C

• D

Which statement describes the structure of an ionic compound?

• It is a giant lattice of oppositely charged ions.

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

• It is a giant molecule of oppositely charged ions.

• It is a simple molecule of oppositely charged ions.

Propane burns in oxygen. C₃H₈ + xO₂ → 3CO₂ + yH₂O. Which values of x and y balance the equation?

• x = 5, y = 4

• x = 7, y = 4

• x = 10, y = 8

• x = 13, y = 8

A tablet contains 0.080 g of ascorbic acid (Mᵣ = 176). What is the concentration of ascorbic acid when one tablet is dissolved in 200 cm³ of water?

• A 9.1 × 10⁻⁵ mol/dm³

• B 4.5 × 10⁻⁴ mol/dm³

• C 9.1 × 10⁻² mol/dm³

• D 2.3 × 10⁻³ mol/dm³

Which statement about the electrolysis of copper(II) sulfate solution using carbon electrodes is correct?

• A A colourless gas is produced at the anode.

• B A colourless gas is produced at the cathode.

• C The colour of the electrolyte remains the same.

• D The mass of both electrodes remains constant.

Aluminium metal is extracted from aluminium oxide by electrolysis. Which ionic half-equation describes a reaction that occurs at the named electrode?

• A

• B

• C

• D