Ethene reacts with hydrogen to form ethane according to the balanced equation
C2H4(g)+H2(g)⟶C2H6(g)
For the reaction as written, ΔH=−136kJmol−1 at 298K. A sample containing 5.60g of ethene undergoes complete hydrogenation under constant-pressure conditions.
(a) Calculate the number of moles of ethene in the sample.
(b) Determine the heat released, in kilojoules, when the sample is completely hydrogenated.
(c) Indicate the sign of q for the system and classify the process as exothermic or endothermic, citing numerical evidence from part (b).