Search our library of Chemistry A Level questions

Top answers

Chemistry

A Level

Given is a following reaction at equilibrium: N2(g) + 3H2(g) ⇄ 2NH3(g), ΔH < 0. What will be the effect of changing the following conditions on the system? 1. Increasing pressure. 2. Decreasing temperature. 3. Adding a catalyst. 4. Adding HCl(g).

The correct approach to this question is to use the Le Chatelier's principle, which states that when you change conditions of a system at equilibrium, the system counteracts the change - a new equilibrium...

Answered by Maciej K. • Chemistry tutor

19083 Views

At what temperature would 0.05 moles of nitrogen gas occupy 1000cm^3 at 50kPa?

Ideal gas equation: pV=nRT Rearrange to get T: T=pV/nR Convert pressure to Pa: 50 x 1000 = 50,000 Convert volume to m^3: 1000 / (100)^3 = 0.001 Insert to find temperature: T = (50,000 x 0.001) / (0.05 x 8...

Answered by Amy H. • Chemistry tutor

1798 Views

Describe the mechanism for bromination across a double bond

This mechanism is an example of an electrophillic addition reaction.

Firstly consider the approach of a Br2, and how that bond will develop an induced dipole as a result of the high electron densit...

Answered by Lewis O. • Chemistry tutor

2487 Views

What are the different types of intermolecular forces?

There are three types of intermolecular forces; 1. Van der Waal forces 2. Dipole-dipole forces 3. Hydrogen bonding Van der waals are the weakest and hydrogen bonding is the strongest. Van der Waal forces ...

Answered by Iona M. • Chemistry tutor

18699 Views

Draw the shape of an SF6 and SF4 molecule, indicating bond angles and any lone pairs which may influence these. What shape is the SF6 molecule?

Sulfur is a group six element, meaning it can form up to six bonds with halogen atoms such as F or Cl. In the instance where only four valence electrons of S are bonded to the halogens, the remaining two ...

Answered by Seb D. • Chemistry tutor

11564 Views