Exam Questions

Question 1

Explain how atmospheric methane molecules can contribute to global warming. (2)

Answer 1

Methane molecules absorb IR radiation (reflected from the surface of Earth) causing the bonds inside the molecule to vibrate.

Question 2

One way scientists hope to minimise global warming is by developing Carbon Capture and Storage (CCS) techniques.
Describe two of these CCS techniques (2)

Answer 2

Liquid CO2 injected deep under oceans.

CO2 stored in geological formations e.g. old mines.

Question 3

Suggest why poly(ethenol) dissolves in water. (2)

Answer 3

Poly(ethenol) contains many hydroxyl groups, which form H-bonds with water molecules.

Question 4

Describe examples of environmental damage that may result from carbon monoxide and hydrogen chloride. (2)

Answer 4

CO is poisonous gas.

HCl is an acidic gas, which dissolves in water to form acid rain.

Question 5

Outline the methods developed by chemists to reduce environmental damage caused by incineration. (2)

Answer 5

HCl is acidic gas and causes acid rain. It can be put through a base to stop it from entering the atmosphere.

CO can be prevented from entering atmosphere by developing ways to make sure all the CO is completely combusted or fully oxidised to CO2.

Question 6

Describe, using the orbital overlap model, how the p-bond in an alkene is formed. (2)

Answer 6

pi bonds are formed by the sideways overlap of 2 p orbitals.

A pi bond is found above and below the plane of the molecule

Question 7

What do curly arrows always show in reaction mechanisms? (1 mark)

Answer 7

Movement of a pair of electrons

Question 8

Which property explains the low reactivity of alkanes? (1 mark)

Answer 8

High C-C bond enthalpy