[HusamEddin]

waiting

[juanrga]

thanks alot my friend
my exam travelled to the next Monday
mmmmm
some thing wrong happened
while I was turning my pages (my chemistry notebook)
I found that my doctor told us that ΔE = Qrev. - w
where Qrev. means Q(reversible)
this made me crazy
my knowledge that (q) here is not necessery to be reversible !!!

can you explain please !

ΔE = Q - w

where heat Q can be due to reversible process or not.

Chemists prefer to use the modern form (this is the recommended form)

ΔE = Q + W

where W = -w

The law ΔE = Q + W is valid for both reversible and irreversible processes.

[HusamEddin]

thank you very much my friend .  understood