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Energetics

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Hi I am having trouble working these things out, I don't no if I put the right molecules in each place or what can someone tell me how to work these out in quite a simple form please

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Reply 1

thefatone

Original post by robzpotter

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Hi I am having trouble working these things out, I don't no if I put the right molecules in each place or what can someone tell me how to work these out in quite a simple form please

so in the empty form below on the far left i put in 2C+3H2+0.5O2 in the right i put CH3CH2OH and in the bottom i put 2C+6H+O

Reply 2

robzpotter

Original post by thefatone

so in the empty form below on the far left i put in 2C+3H2+0.5O2 in the right i put CH3CH2OH and in the bottom i put 2C+6H+O

Thanks!

But how do you then work it out?

Reply 3

thefatone

Original post by robzpotter

Thanks!

But how do you then work it out?

so you have enthalpy of combustion so arrows go from equation to elements at the bottom

you have 2C and 3H2
so you have 2(-393) and 3(-286)
and the other arrow on the right you have -1368

so now it's like vectors

values of 2C and 3H2 - value of Ch3CH2OH