The Student Room Group
Uni students - Complete our survey >>
Uni students - Complete our survey >>
Uni students - Complete our survey >>

As chem

Help!! Test tomorrow and I’m stuck23C12C29-8444-456F-91C7-D95A1EC3435D.jpegA2E88528-6BEE-4DCD-B8A0-DD942C7AF86B.jpeg on the second question
(edited 3 years ago)
Reply 1
Avatar for ram8_
ram8_
13
Original post by Danyal124
Help!! Test tomorrow and I’m stuck23C12C29-8444-456F-91C7-D95A1EC3435D.jpegA2E88528-6BEE-4DCD-B8A0-DD942C7AF86B.jpeg on the second question

Well we need part (a) in order to obtain an answer.. or is my screen bugged and I can't see it?
Original post by ram8_
Well we need part (a) in order to obtain an answer.. or is my screen bugged and I can't see it?

CO2H has MR = 12 + 32 + 1 = 45

Rest of molecule has mass 88 - 45 = 43

43 is C3H7

so C3H7CO2H is the molecule, the MF is C4H8O2
Reply 3
Avatar for ram8_
ram8_
13
Original post by golgiapparatus31
CO2H has MR = 12 + 32 + 1 = 45

Rest of molecule has mass 88 - 45 = 43

43 is C3H7

so C3H7CO2H is the molecule, the MF is C4H8O2

Ah I see. But I presume that part (a) would give us an empirical formula and we can see the ratio between the molecular mass and the empirical formula mass to calculate the molecular formula, which I think would have been easier?
Original post by ram8_
Ah I see. But I presume that part (a) would give us an empirical formula and we can see the ratio between the molecular mass and the empirical formula mass to calculate the molecular formula, which I think would have been easier?

Part (a) [1 in the picture] asks for the Mr which they wrote as 88.

Part (b) [2 in the picture] asks for the molecular formula which can be worked out from the mass spectrum.

They didn't give the empirical formula
Reply 5
Avatar for user342
user342
12
Original post by golgiapparatus31
Part (a) [1 in the picture] asks for the Mr which they wrote as 88.

Part (b) [2 in the picture] asks for the molecular formula which can be worked out from the mass spectrum.

They didn't give the empirical formula

I thought 2 in the picture was part c?
Reply 6
Avatar for ram8_
ram8_
13
Original post by golgiapparatus31
Part (a) [1 in the picture] asks for the Mr which they wrote as 88.

Part (b) [2 in the picture] asks for the molecular formula which can be worked out from the mass spectrum.

They didn't give the empirical formula

Aren't the questions in the pictures part (b) and (c)?
Original post by user342
I thought 2 in the picture was part c?

Sorry. I didn't see that as it's nearly cut off. You are right. Then the empirical formula must be used along with the Mr.
My method in post 3 gets zero marks in the exam.
Original post by ram8_
Aren't the questions in the pictures part (b) and (c)?

They are part (a) and (c) I believe
Reply 9
Avatar for user342
user342
12
Original post by golgiapparatus31
They are part (a) and (c) I believe

Do you have a picture of part b?
Original post by user342
Do you have a picture of part b?

Nope

Quick Reply

Related discussions

Latest

Trending

Trending

Articles for you