One step in making para-aminobenzoic acid, paba, an ingredient in some
suntan lotions, involves replacing one of the hydrogen atoms in a toluene molecule with
an -no2 group, directly opposite the -ch3 group. calculate the percent yield if 550 g of
toluene added to an excess of nitric acid provides 305 g of the nitrotoluene product.

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.

the correct answer would be d. hope this !

the answer is c.the valence of the atoms combine .