2C(s)+H2(g)+227.4kJ -> C2H2(g) is an endothermic reaction.

Question

If 682.2 kilojoules are absorbed, how many moles of C2H2(g) are produced?

Answer 1

227.4 kJ per 1 mole C2H2.
682.2 kJ x (1 mol C2H2/227.4 kJ) = ??
Note how kJ in the numerator cancels with kJ in the denominator which gets rid of the unit we don't want and converts to the unit (mole C2H2) which we want to keep. Check my work.

Answer 2

Each mole of C2H2 formed absorbs 227.4 kJ

Divide 682.2 kJ by 227.4 kJ/mol
to get the answer

Answer 3

THe answer is 3