Question

A chemical reaction is run in which 736 Joules of work is done by the system and the internal energy changes by -1370 Joules.

pls help me

Answer 1

I don't see a question.

Answer 2

I’m guessing you need the Rxn Enthalpy. It’s the only given data item missing for the 1st Law equation…
ΔU = q + w => q = ΔU – w = (-1370 J) – (- 736 J) = (-1370 + 736) J = - 634 Joules exothermic heat of rxn.
ΔU = -1370 Joules (given)
w = -736 Joules (expansion work)*
*expansion => system is working (pushing back) on the surroundings => w < 0.
*compression => surroundings working (compressing) on the system => w > 0.

Answer 3

ご投資にかかる手数料等およびリスクについて｜お知らせ｜企業・IR情報｜株のことならネット証券会社【カブドットコム】