Exam questions

Question 1

What is meant by the term isotopes

Answer 1

An atom of an element with the same number of protons and a different number of neutrons.

Question 2

Chemists are able to predict the shape of a simple covalent molecule from the number of electron pairs surrounding the central atom

Explain how this enables chemists to predict the shape

Answer 2

Pairs of electrons repel

Shape is determined by number of lone and bond pairs

Question 3

First ionisation energy

Answer 3

Energy required to remove an electron from each atom in one mole of gaseous atoms

Question 4

First ionisation energy of oxygen is less than the first ionisation energy of fluorine

Explain why

Answer 4

Oxygen has a higher atomic radius

Smaller nuclear charge

Weaker nuclear attraction

Question 5

Sulfate (IV)

Answer 5

SO3 2-

Question 6

Compound of magnesium that could be used to treat heartburn

Answer 6

Magnesium hydroxide

Question 7

Metal carbonate + acid >

Answer 7

Metal?? + water + carbon dioxide

Question 8

In another experiment, a student attempts to make a solution of strontium chloride by adding chlorine water to aqueous strontium bromide

Describe what the student would observe

Answer 8

Mixture would turn orange

Question 9

Chlorine is more reactive than bromine

Explain why

Answer 9

Chlorine gains an electron more easily

Chlorine is smaller and has less electron shielding

Stronger nuclear attraction

Question 10

Explain why there is a difference in the boiling points of HCl and F2

Answer 10

F2 has induced dipole attraction

HCl has permanent dipole attraction

Induced is weaker

Permanent requires more energy to overcome