Is this exothermic or endothermic? EXPLAIN

C2H2+H2-----> C2H4

Is this exothermic or endothermic? EXPLAIN

C2H2+2H2---->C2H6

Is this exothermic or endothermic? EXPLAIN
C2H4+ H2 ----> C2H6

2 answers

dHrxn = (n*dHproducts) - (n*dHreactants)
Then check the sign. If dHrxn is - the reaction is exothermic; if dHrxn is positive the reaction is endothermic.
exo