A level Chemistry PAG- Help

Watch this thread
GiorgiosROu
Badges: 3
Rep:
? You'll earn badges for being active around the site. Rep gems come when your posts are rated by other community members.
#1
Report Thread starter 5 months ago
#1
1.3- Determination of the formula for magnesium oxide

Hi guys,

So the question is to find the amount in moles of Mg and O atoms in magnesium oxide that you prepared. then the empirical formula.

Idk where I went wrong but it does not equal to a 1:1 ratio, I'm stuck on the empirical formula bit (the question mark)Name:  IMG_7344 2.jpeg
Views: 108
Size:  183.1 KB
Attached files
Last edited by GiorgiosROu; 5 months ago
0
reply
TriplexA
Badges: 18
Rep:
? You'll earn badges for being active around the site. Rep gems come when your posts are rated by other community members.
#2
Report 5 months ago
#2
(Original post by GiorgiosROu)
1.3- Determination of the formula for magnesium oxide

Hi guys,

So the question is to find the amount in moles of Mg and O atoms in magnesium oxide that you prepared. then the empirical formula.

Idk where I went wrong but it does not equal to a 1:1 ratio, I'm stuck on the empirical formula bit (the question mark)Name:  IMG_7344 2.jpeg
Views: 108
Size:  183.1 KB
Your workings seem fine to me. I think the answer is just Mg5O2
0
reply
Trumbles
Badges: 12
Rep:
? You'll earn badges for being active around the site. Rep gems come when your posts are rated by other community members.
#3
Report 5 months ago
#3
Are these the results of an actual experiment? I wonder whether some of the magnesium was left unreacted.

I realise that you want to get to a formula of MgO, but from the start it looks like the amount of mass of magnesium is too great compared to the mass of oxygen. It isn't that an error in your calculations has created that problem. (Strictly speaking the Oxygen should be 0.0025/0.0025 but obviously the answer is still '1'.)

So I think going for a formula like Mg5O2 is probably the best you can do now and hope for the mark on an error carried forward basis.
You could add "I was expecting a formula of MgO – possibly some of the magnesium remained unreacted."
0
reply
X

Quick Reply

Attached files
Write a reply...
Reply
new posts
Back
to top
Latest
My Feed

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.

Personalise

How did your AQA GCSE English Language Paper 1 go?

Loved the paper - Feeling positive (70)
19.23%
The paper was reasonable (134)
36.81%
Not feeling great about that exam... (108)
29.67%
It was TERRIBLE (52)
14.29%

Watched Threads

View All
Latest
My Feed