You are Here: Home

# Equation help Watch

1. Why is the formula for lithium bromide LiBr.

I understand that there Lithium has a 1+ charge and Bromine has a 1- charge. But isn't bromine a diatomic molecule - so shouldn't the formula be 2LiBr?

2. Hi everyone!

Why is the formula for lithium bromide LiBr.

I understand that there Lithium has a 1+ charge and Bromine has a 1- charge. But isn't bromine a diatomic molecule - so shouldn't the formula be 2LiBr?

3. (Original post by park1996)
Hi everyone!

Why is the formula for lithium bromide LiBr.

I understand that there Lithium has a 1+ charge and Bromine has a 1- charge. But isn't bromine a diatomic molecule - so shouldn't the formula be 2LiBr?

Diatomic just means that is is found as the dimer X2 in it's natural form. This does not effect the compounds it forms. Br typically only forms one covalent bond and is diatomic in its elemental form. Equally oxygen and nitrogen are diatomic but form 2 and 3 covalent bonds respectively.

LiBr is a giant ionic lattice so placing a number in-front of the empirical formula is pointelss. In reality a crystal of LiBr would actually be somewhere of the order (10^24)LiBr
4. The formula is as such because the negative and positive charges cancel, thus giving LiBr
5. well, what I learnt was this:

The ion for Li is Li+1 and the ion for Br is Br-1
So, you swap the powers (in this case they stay the same) and drop them (Li1Br1).
You don't need 1's so get rid.

Therefore, LiBr

Hope that helps

TSR Support Team

We have a brilliant team of more than 60 Support Team members looking after discussions on The Student Room, helping to make it a fun, safe and useful place to hang out.

This forum is supported by:
Updated: April 1, 2013
Today on TSR

### Last-minute PS help

100s of personal statements examples here

### More pressure for kinky sex?

Discussions on TSR

• Latest
• ## See more of what you like on The Student Room

You can personalise what you see on TSR. Tell us a little about yourself to get started.

• Poll
Discussions on TSR

• Latest
• ## See more of what you like on The Student Room

You can personalise what you see on TSR. Tell us a little about yourself to get started.

• The Student Room, Get Revising and Marked by Teachers are trading names of The Student Room Group Ltd.

Register Number: 04666380 (England and Wales), VAT No. 806 8067 22 Registered Office: International House, Queens Road, Brighton, BN1 3XE

Reputation gems: You get these gems as you gain rep from other members for making good contributions and giving helpful advice.