## Calculating number of moles of an element

Emilie_Paltrinieri_1K
Posts: 39
Joined: Wed Sep 30, 2020 10:07 pm

### Calculating number of moles of an element

When calculating the number of moles of an element we always use 100g. I was wondering if we use 100g just for semplicity, and if there is any particular case where we should consider different quantities.

Quentin Scarborough 1A
Posts: 42
Joined: Wed Sep 30, 2020 9:59 pm
Been upvoted: 1 time

### Re: Calculating number of moles of an element

We use 100g simply because it is easier to visualize the mass percentage composition. You could use other values but it would make it more difficult. It just depends on the method that works best for you.

Chenning Yang Dis3l
Posts: 38
Joined: Fri Oct 09, 2020 12:16 am

### Re: Calculating number of moles of an element

I think 100g works the best for most cases since it makes the numbers much simpler.

305392242
Posts: 37
Joined: Wed Sep 30, 2020 9:47 pm

### Re: Calculating number of moles of an element

100g is a tool to help conceptualize the elemental proportions of a molecule to equal 100%. It's an arbitrary number that always works in those problems.

Sachi Sengupta 3B
Posts: 36
Joined: Wed Sep 30, 2020 9:49 pm

### Re: Calculating number of moles of an element

You're completely right! We use 100g for simplicity since we are usually given the mass percent composition and that way it an easy conversion from percent to grams of the element.

Claudia_Danysh_2C
Posts: 43
Joined: Wed Sep 30, 2020 9:58 pm

### Re: Calculating number of moles of an element

I also think that we pretend we have 100 grams in total because it makes the calculations easier because when you're first learning how to figure out empirical and molecular formulas, pretending that there are 100 grams in total just makes it easier to approach each problem since you start each problem the same way!

Emma_Barrall_1D
Posts: 35
Joined: Wed Sep 30, 2020 9:55 pm

### Re: Calculating number of moles of an element

Assuming 100g for percent composition just helps with simplicity!

Thomas Gimeno
Posts: 35
Joined: Wed Sep 30, 2020 9:49 pm

### Re: Calculating number of moles of an element

It 100% for simplicity. When you have 45% of something, its a lot easier to just write it as 45g then as an obscure number representing a different total

905389581
Posts: 34
Joined: Wed Sep 30, 2020 10:11 pm

### Re: Calculating number of moles of an element

Yea im pretty sure we use it just to make the calculations simpler!

Bai Rong Lin 3I
Posts: 36
Joined: Wed Sep 30, 2020 9:54 pm

### Re: Calculating number of moles of an element

Emilie_Paltrinieri_1K wrote:When calculating the number of moles of an element we always use 100g. I was wondering if we use 100g just for semplicity, and if there is any particular case where we should consider different quantities.

I believe it is cause 100g is much easier for simplification, and also it was one of the things I was first taught with and more used to using!

Edward Castro
Posts: 35
Joined: Wed Sep 30, 2020 9:32 pm