Search our library of Chemistry A Level questions

Top answers

Chemistry

A Level

Why are some complex ions coloured?

Ligands causes d orbitals to split. Electrons get excited to higher energy levels from ground state. Visible light is absorbed to promote electron to a higher energy leve...

Answered by Juliet O. • Chemistry tutor

1996 Views

Why is Phenol more reactive than Benzene in electrophilic substitution reactions?

Phenol has the -OH group and the oxygen has a lone pair of electrons which are donated into the Benzene ring and activate the ring which make it more sus...

Answered by Juliet O. • Chemistry tutor

7475 Views

How does free radical substitution work?

(This explanation would make use of diagrams on a whiteboard)It is useful to break this down into three steps: 1- the initiation step. Let's take the reaction between Cl₂ and CH₄.

Answered by Tom H. • Chemistry tutor

1986 Views

What is an empirical formula and how do I calculate it?

The empirical formula of a compound is the simplest ratio of the atoms present in that compound and it can be calculated relatively easily by following a few simple steps:Let's use an example of a hydroca...

Answered by Victoria O. • Chemistry tutor

2762 Views

What trends are shown as you go down group 2 of the periodic table?

Group 2 (the alkaline earth metals) show many different trends. As you go down, the size of the atoms increases. This is due to the fact that each element has an extra full main level of electrons compare...

Answered by • Chemistry tutor

11830 Views