chemistry question helpp (1 Viewer)

[DepressedPenguino]

What mass of zinc can be obtained from the reaction of 16.3g of zinc oxide according to the following equation.
ZnO (s) + C (s) -> Zn (s) + CO (g)

I orginally got 16.3g as my answer... but now I think it is 65.39g ..

 

[DepressedPenguino]

Never mind! They're both wrong I think.... I got 13.078g now.. for the mass of zinc. Haha..

 

[ghuy]

Hey,

Are you sure the reaction is correct? If I'm not wrong it should be
2ZnO (s) + C (s) -> 2Zn(s) + CO2(g)
Based off my reaction this is my working:
n=mass/Molecular Mass
n(ZnO)=16.3/(65.39+16)=0.20027moles
n(ZnO):n(Zn)=0.20027moles (based off the molar ratios)
Therefore n(Zn)=0.20027moles
n=mass/Molecular Mass
0.20027=m/65.39
m= 0.20027 x 65.39
m=13.0956g

But technically the answer should be the same if you used my or your reaction due to the fact that they both have the same molar ratios, although you may be penalised if you wrote CO instead of CO2.

Hope I could help

 

[ghuy]

Never mind! They're both wrong I think.... I got 13.078g now.. for the mass of zinc. Haha..

Haha I was a bit too late lol

 

[DepressedPenguino]

Different periodic table... results slightly different

 

[DepressedPenguino]

One more question guys.
Octane, C8H18, when burnt in oxygen produces carbon dioxide and water. When 91.2g of octane is burnt, calculatr the following:
The mass of oxygen consumed?
I worked out the chemival eqn btw. 2 C8H18+ 25 O -> 16CO2 + 18H2O (balanced)

Is the answer 160g ?

 

[DepressedPenguino]

Hey,

Are you sure the reaction is correct? If I'm not wrong it should be
2ZnO (s) + C (s) -> 2Zn(s) + CO2(g)
Based off my reaction this is my working:
n=mass/Molecular Mass
n(ZnO)=16.3/(65.39+16)=0.20027moles
n(ZnO):n(Zn)=0.20027moles (based off the molar ratios)
Therefore n(Zn)=0.20027moles
n=mass/Molecular Mass
0.20027=m/65.39
m= 0.20027 x 65.39
m=13.0956g

But technically the answer should be the same if you used my or your reaction due to the fact that they both have the same molar ratios, although you may be penalised if you wrote CO instead of CO2.

Hope I could help

Yeah I'm absolutely certain that my eqn is correct :^)

 

[turntaker]

What mass of zinc can be obtained from the reaction of 16.3g of zinc oxide according to the following equation.
ZnO (s) + C (s) -> Zn (s) + CO (g)

I orginally got 16.3g as my answer... but now I think it is 65.39g ..

Is this in Metals?

 

[DepressedPenguino]

Is this in Metals?

I think so...