## Finding the amount in moles of a part of a molecule

Amy Luu 2G
Posts: 92
Joined: Wed Sep 18, 2019 12:19 am

### Finding the amount in moles of a part of a molecule

I'm confused on how to approach problem E.23 c)
Calculate the amount in moles of F- ions in 25.2 kg of UF6.
I started by finding the molar mass of UF6 which was 352.03 g/mol but I'm unsure what to do next.

Kevin Antony 2B
Posts: 71
Joined: Sat Sep 07, 2019 12:16 am

### Re: Finding the amount in moles of a part of a molecule

First you'll have to divide the mass of UF6 by the molar mass. This gives you the moles of UF6 present. As there are 6 moles of F- in 1 mol of UF6, multiply the result by 6. This should give you the moles of F- ions.

Izzie Capra 2E
Posts: 91
Joined: Sat Sep 07, 2019 12:19 am

### Re: Finding the amount in moles of a part of a molecule

First, you have to convert 25.2kg to g. Then you will divide by the molar mass of UF6. Now you have moles of UF6, so you will then see that there are 6 moles of F- for every 1 mole of UF6. Multiply by 6 to get moles of F- ions.

Chantel_2I
Posts: 90
Joined: Sat Sep 07, 2019 12:19 am

### Re: Finding the amount in moles of a part of a molecule

In this problem, it's important to identify the ratio of 6 F- ions for every UF6 molecule. Once you have identified that, it becomes a simple conversion problem, converting the mass of UF6 to moles using the molar mass. At that point, you use the ratio of 1:6 to find the number of moles of F- ions.