Chemistry Last minute help

Watch this thread
Emmaboyd
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.
#1
Report Thread starter 5 years ago
#1
Hey guys I'm so stuck on this w and as its multiple choice there's no explanation in ms!

10cm3 of a pure hydrocarbon was completly combusted in 70cm3 oxygen (excess).

The final gaseous mixture was 30cm3 Carbon dioxide and 20cm3 unreacted oxygen.

What is the formula of the hydrocarbon?
A) C2H4
B)C2H6
C) C3H6
D)C3H8

Thanks
0
reply
Dynamic_Vicz
Badges: 16
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 years ago
#2
Volume is proportional to the amount of a substance.

You know that the oxygen is in excess so the limiting agent is the hydrocarbon.

Take 10 cm³ to be proportional to 1 mol.

You know that for a complete combustion : hydrocarbon + AOxygen - > Bcarbon dioxide + Cwarter where A, B and C are the relative moles of each substance in the reaction.

For an incomplete combustion: hydrocarbon + DOxygen - > Ecarbon monoxide + Fwater where D, E and F are the relative moles of each substance in the reaction.

Balance the constants to get the hydrocarbon.
0
reply
Emmaboyd
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 Thread starter 5 years ago
#3
Thank you!
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

Were exams easier or harder than you expected?

Easier (21)
27.63%
As I expected (23)
30.26%
Harder (28)
36.84%
Something else (tell us in the thread) (4)
5.26%

Watched Threads

View All