when 1.255 g of X reacts completely with 3.2 g of Y , Z is the only product of the reaction. what is the total mass of Z, expressed to the proper number of significant figures

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.