Search our library of Chemistry questions

Top answers

Chemistry

All levels

Draw a dot and cross diagram of a Chlorine molecule showing the outer electrons only.

Chlorine has seven outer electrons. Electrons like to be in pairs. In one Chlorine atom, there are three pairs and one lonely electron which doesn't have a pair. (draw). So two Chlorine atoms form a Chlor...

Answered by Lisa M. • Chemistry tutor

15036 Views

Write a word equation for the reaction between marble chips and hydrochloric acid. (1) How could the rate of reaction be increased and why? (7)

i) Marble chips are made from calcium carbonate.Hydrochloric acid + calcium carbonate -> Calcium chloride + water + carbon dioxideii) The rate of reaction can be increased by increasing the concentrati...

Answered by Michelle K. • Chemistry tutor

32091 Views

How can you work out, using the changes in oxidation numbers, which compound out of KCl, KBr and KI has the greatest reducing power?

We can work this out by observing the changes in oxidation state of sulphur in concentrated sulphuric acid (H₂SO₄) when this compound reacts with KCl, KBr and KI individually.
A...

Answered by Sarah P. • Chemistry tutor

5794 Views

Explain what happens to a crystal of iodine when it is heated (5marks)

A crystal of iodine sublimes from its solid state to its gaseous state without turning into a liquid. Iodine forms a molecular covalent crystal. This means that there are strong covalent ...

Answered by Meghna I. • Chemistry tutor

21079 Views

Sodium chloride and sodium metal can both conduct electricity under differing conditions. Give the conditions required for each to conduct electricity and explain how each conducts electricity.

Sodium chloride will conduct electricity only when it is in a liquid state or in solution, this is because the ions are free to move in this state, allowing them to carry charge and conduct electricity. S...

Answered by Tanmayi J. • Chemistry tutor

32612 Views