Which of the following represents a hydrogen displacement reaction? Group of answer choices 2Al(s) + 3H 2SO 4(aq) → Al 2(SO 4) 3(aq) + 3H 2(g) 2C 2H 6(g) + 7O 2(g) → 4CO 2(g) + 6H 2O(l) 2KBr(aq) + Cl2(g) → 2KCl(aq) + Br2(l) CaBr2(aq) + H2SO4(aq) → CaSO4(s) + 2HBr(g) N 2(g) + 3H 2(g) → 2NH 3(g)

answer: enthalpy

explanation:

for a exothermic reaction, the energy is released i.e. the energy of the products is lower than the energy of the reactants.

= enthaply

= energy of products

= energy of reactants

as , thus comes out to be negative. negative value of enthalpy shows that the reaction is exothermic.