Question

8. What volume of oxygen is required for the complete combustion of a mixture of 5 cm3 of CH4 and 5 cm3 of C2H4 ?
I just want help . not the ANSWER please .thank you :)

Answer 1

@JMark @atlas @madrockz @thomaster

Answer 2

Start with the reaction equation

Answer 3

reaction of methane with oxygen @thomaster

Answer 4

after complete combustion everything becomes Co2 and water

Answer 5

d = m/V ???

Answer 6

what's that?

Answer 7

density = mass / volume . Is i have to put this ??

Answer 8

now why would you need density?

Answer 9

um...to find volume of oxygen I think so ...

Answer 10

PV = nRT is valid for all gases at standard conditions
So if Pressure and Temperature are constant equal volume will contain equal moles
SOlve the question using moles and replace them with volume afterwards

Answer 11

You need to convert cm3 to moles. In this case that's easy since 1 mol gas = 22.4 liter.
1 liter = 1000 cubic centimeters

Answer 12

@thomaster i don't think that is necessary

Answer 13

um ..getting confused :/

Answer 14

Since moles and volume are equivalent here........................solving the question in volume is sufficient

Answer 15

Yea just start with writing the chemical equation

\(\Large CH_4+O_2\to?\)

Answer 16

ok ..:)

Answer 17

CH4 + 2O2 ---> CO2 + 2H2O ..

Answer 18

That's correct :)

Answer 19

so the next step please :) ??

Answer 20

Now the mol ratio is: 1 mol CH4 reacts with 2 mol O2 to produce 1 mol CO2 and 2 mol H2O
we only need the first part: 1 mol CH4 reacts with 2 mol O2, so CH4:O2 = 1:2

We have 5cm3 CH4, how many cm3 O2 would we need?

Answer 21

10cm3 ...

Answer 22

exactly :D
Now can you do the same for the second one? C2H4?

Answer 23

C2H4 + 3O2 --> 2CO2 + 2H2O
so C2H4 : O2 = 1 : 3

for 5cm3 of C2H4 we need 15 cm 3 O2

Answer 24

@thomaster

Answer 25

correct \(\LARGE\ddot\smile\)

Answer 26

so our answer is 25 cm 3 O2 ...:D

Answer 27

no 5 * 3 = 15 O2

Answer 28

@thomaster : she was saying the overall answer

Answer 29

@sarah786 : you are right

Answer 30

oh that way, in that case 10+15 = 25 yea

Answer 31

yeah overall answer :)

Answer 32

Thanks you so much guys :)...But this is the only one .I need your help for more problems too ..so I'll tag you when I need ur help ..ok :) ??

Answer 33

sure :)