/sci/ - Science & Math

[Jim Profit !!rrRSu3zNuiR No.2194817]

This ones for the chemfags.

How do I workout the standard enthalpy of formation of CH3OCH3 given that the standard enthalpy of combustion for

Carbon = -395kjmol
Hydrogen = -286kjmol
CH30CH3 = - 1460kjmol

This is all i have been given to work with but wont i need to know the change for oxygen?

pic related its the wildebeesty boys

[Jim Profit !!rrRSu3zNuiR No.2194889]

bamp

[Anonymous No.2194902]

The enthalpy of formation for a pure element is 0.

[Anonymous No.2194911]

C + O2 = CO2
H2 + 1/2*O2 = H2O
CH3OCH3 + 3O2 = 3H2O + 2CO2
These are the reactions you have the enthalpy values for, add/subtract them in whatever amounts you need to get CH3OCH3

[fizixfag !yOO9L7sT1k No.2194930]

>>2194902
>CH3OCH3
>Pure element

[Anonymous No.2194948]

Who knows if it's readable but here's an answer.

Chemfags can suck it, ChemEfag here capable of everything and more...

[Anonymous No.2194951]

[Anonymous No.2194961]

>>2194930

I was referring to O2. CH3OCH3 isn't even an element.

[Anonymous No.2194970]

>>2194961
As if O2 is an element?

[Jim Profit !!rrRSu3zNuiR No.2194984]

>>2194970

Lol

Thanks guys. Ill see if i can take what u guys have shown me and figure this shit out.

[Jim Profit !!rrRSu3zNuiR No.2195044]

Wait a sec...

Wouldnt this equation work aswell?

2C + 3H20 ----> CH3OCH3 + O2

[fizixfag !yOO9L7sT1k No.2195060]

>>2195044
I would imagine that is a very unfavorable reaction and thus the direct data probably isn't available.

[Anonymous No.2195084]

>>2195044
That's a balanced chemical equation but like above said, it won't be at all energetically likely. AND it doesn't help you answer the problem. Work with what you've got in the problem statement, and with that you get this solution
>>2194951