# gas calculation

Announcements
#1
20cm3 of hydrocarbon needed 90cm3 of oxygen for complete combustion. 60cm3 is CO2 was produced. All volumes were measured at rtp and pressure. Find the formula of the hydrocarbon.
0
1 year ago
#2
(Original post by btsarmyy)
20cm3 of hydrocarbon needed 90cm3 of oxygen for complete combustion. 60cm3 is CO2 was produced. All volumes were measured at rtp and pressure. Find the formula of the hydrocarbon.
Done that ... now what?
0
#3
(Original post by charco)
Done that ... now what?
i don't know how to work out the formula
0
1 year ago
#4
(Original post by btsarmyy)
i don't know how to work out the formula
All hydrocarbons contain only hydrogen and carbon.
When burned completely all hydrogen forms water and all carbon forms carbon dioxide.
Avogadro's law says that the gas volume is directly proportional to the number of moles.
0
#5
(Original post by charco)
All hydrocarbons contain only hydrogen and carbon.
When burned completely all hydrogen forms water and all carbon forms carbon dioxide.
Avogadro's law says that the gas volume is directly proportional to the number of moles.
that doesn't exactly help me??
0
#6
i have no idea how to work out the formula???

20cm3 of hydrocarbon needed 90cm3 of oxygen for complete combustion. 60cm3 is CO2 was produced. All volumes were measured at rtp and pressure. Find the formula of the hydrocarbon.
0
1 year ago
#7
(Original post by btsarmyy)
i have no idea how to work out the formula???

20cm3 of hydrocarbon needed 90cm3 of oxygen for complete combustion. 60cm3 is CO2 was produced. All volumes were measured at rtp and pressure. Find the formula of the hydrocarbon.
Please do not make multiple threads on the same subject. It's spam.
0
#8
(Original post by charco)
Please do not make multiple threads on the same subject. It's spam.
but you didnt explain it too me properly so i asked again ??hoping someone else could explain it
0
1 year ago
#9
(Original post by btsarmyy)
that doesn't exactly help me??
It gives you all of the information that you need to work the answer out for yourself.

All hydrocarbons contain only hydrogen and carbon. - therefore the formula is CxHy
When burned completely all hydrogen forms water and all carbon forms carbon dioxide. Cx ===> xCO2 ; Hy ===> y/2H2O
Avogadro's law says that the gas volume is directly proportional to the number of moles. You can use the gas volumes as if they are moles to get the ratio of moles of each component.
0
X

new posts
Back
to top
Latest

### Oops, nobody has postedin the last few hours.

Why not re-start the conversation?

see more

### Poll

Join the discussion

Talking to current university students (12)
17.39%
Talking to peers going through the same thing (25)
36.23%
Speaking to student ambassadors from the universities (5)
7.25%
Speaking to staff members from universities (1)
1.45%
Using the personal statement builder, library or helper service (7)
10.14%
20.29%
Learning about/speaking to Student Finance England (2)
2.9%
Something else (tell us in the thread) (3)
4.35%