coconut64
Badges: 16
Rep:
?
#1
Report Thread starter 4 years ago
#1
Attachment 607980607982 for q2b I am unsure how it's worked out.

1. How will you be able to deduce that the Mr of coal is just 12 g mol^-1? You are not told the molecular formula for it .

2. The answer suggests that you will work out the heat loss q from the moles of coal * by the enthalpy change of combustion but I don't understand why. Why is q of coal = q of water ?




Thanks
Attached files
0
reply
username986184
Badges: 3
Rep:
?
#2
Report 4 years ago
#2
The question says assume coal is pure carbon. Carbon is in the periodic table!
0
reply
username986184
Badges: 3
Rep:
?
#3
Report 4 years ago
#3
Use Q = mcΔT for 2b)
0
reply
coconut64
Badges: 16
Rep:
?
#4
Report Thread starter 4 years ago
#4
(Original post by TeachChemistry)
The question says assume coal is pure carbon. Carbon is in the periodic table!
So whenever the question states the the compound is made up of carbon, it is okay to assume that the mr is 12?

Also can you help me with my second question?

Thanks
0
reply
coconut64
Badges: 16
Rep:
?
#5
Report Thread starter 4 years ago
#5
(Original post by TeachChemistry)
Use Q = mcΔT for 2b)
I don't really understand why q of the coal equals to q of the water, I always know it as that you would only include the mass of the water in this equation...
0
reply
username986184
Badges: 3
Rep:
?
#6
Report 4 years ago
#6
(Original post by coconut64)
I don't really understand why q of the coal equals to q of the water, I always know it as that you would only include the mass of the water in this equation...
You assume that all of the heat released by the coal burning is transferred to the water to heat it up.
0
reply
coconut64
Badges: 16
Rep:
?
#7
Report Thread starter 4 years ago
#7
(Original post by TeachChemistry)
You assume that all of the heat released by the coal burning is transferred to the water to heat it up.
Thanks.
0
reply
PBC Gyal
Badges: 2
Rep:
?
#8
Report 4 years ago
#8
(Original post by TeachChemistry)
You assume that all of the heat released by the coal burning is transferred to the water to heat it up.
Name:  image.jpg
Views: 133
Size:  504.7 KB
Does anybody know how to work this out? It was from the new Aqa Chem AS paper 2016 Thank You
0
reply
coconut64
Badges: 16
Rep:
?
#9
Report Thread starter 4 years ago
#9
(Original post by PBC Gyal)
Name:  image.jpg
Views: 133
Size:  504.7 KB
Does anybody know how to work this out? It was from the new Aqa Chem AS paper 2016 Thank You
Hey I just worked this out but can't find the paper nor the mark scheme, mind telling me the answer ? Cheers
0
reply
charco
Badges: 18
Rep:
?
#10
Report 4 years ago
#10
(Original post by coconut64)
Hey I just worked this out but can't find the paper nor the mark scheme, mind telling me the answer ? Cheers
about -11,760 kJ
0
reply
PBC Gyal
Badges: 2
Rep:
?
#11
Report 4 years ago
#11
(Original post by coconut64)
Hey I just worked this out but can't find the paper nor the mark scheme, mind telling me the answer ? Cheers
Hey and yes I got around 11570KJ it was the AqaChem new spec done in2016
0
reply
PBC Gyal
Badges: 2
Rep:
?
#12
Report 4 years ago
#12
(Original post by TeachChemistry)
Use Q = mcΔT for 2b)

Name:  image.jpg
Views: 160
Size:  498.0 KBAttachment 609428609430Do you know how to work this out? The last image is the graph for the question above please
Attached files
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

Feeling behind at school/college? What is the best thing your teachers could to help you catch up?

Extra compulsory independent learning activities (eg, homework tasks) (18)
7.5%
Run extra compulsory lessons or workshops (35)
14.58%
Focus on making the normal lesson time with them as high quality as possible (43)
17.92%
Focus on making the normal learning resources as high quality/accessible as possible (34)
14.17%
Provide extra optional activities, lessons and/or workshops (63)
26.25%
Assess students, decide who needs extra support and focus on these students (47)
19.58%

Watched Threads

View All