Search our library of Chemistry A Level questions

Top answers

Chemistry

A Level

Explain the trend in first ionisation energy as you go across Period 3

Overall, the first ionisation energies will increase. This is because as you go along the period, the atomic number increases and this causes a stronger electrostatic attraction between the outer electron...

Answered by Charles W. • Chemistry tutor

15829 Views

Sort the following compounds in order of increasing boiling point and explain your reasoning: hydrogen, hydrogen fluoride and hydrogen bromide

Order: hydrogen fluoride > hydrogen bromide > hydrogen.Hydrogen fluoride contains a hydrogen atom bonded directly to a fluorine atom. The fluorine is highly electronegative and so pulls the bonding ...

Answered by Alex M. • Chemistry tutor

4489 Views

a) How can an element be classified as a transition metal, considering only electronic arrangement? (1 mark) b) In terms of electrons, why is aqueous copper(II) sulphate solution red? (3 marks) c) EDTA is a bidentate ligand. What is a bidentate ligand?(2)

a) Partially filled/incomplete d shell.
b) Light is absorbed by an electron, exciting it and is promoted to a higher energy d orbital. The colour seen is the complimentary colour of that absorbed (in...

Answered by James O. • Chemistry tutor

1866 Views

25cm^3 of 0.1M NaOH is reacted with 0.01M HCl until the equivalence point is reached. What volume of HCl was required to be added?

0.025 dm^3 x 0.1 mol dm^-3 = 0.0025 molsince mols must be equal:mols of HCl = 0.0025/0.01 =250cm^3To get to the answer I would first check the student was first able to identify the key words and numbers ...

Answered by Georgina W. • Chemistry tutor

2359 Views

What is covalent character, how does it arise. List a compound it does affect and explain the resulting properties covalent character affects.

Covalent character occurs in ionic bonds when the postive (usually metal) ion is highly charge dense and can polarise the counter ion causing electrons to be shared between the two ions rather than electr...

Answered by Jake V. • Chemistry tutor

24664 Views