The following thermochemical equation is for the reaction of iron(s) with hydrochloric acid(aq) to form iron(II) chloride(s) and hydrogen(g). Fe(s) + 2HCl(aq) FeCl2(s) + H2(g) H = -7.40 kJ When 11.3 grams of iron(s) react with excess hydrochloric acid(aq), kJ of energy are .

–1.49 KJ of energy.

Explanation:

The balanced equation for the reaction is given below:

Fe(s) + 2HCl(aq) —> FeCl2(s) + H2(g)

ΔH = –7.40 kJ

Next, we shall determine the mass of Fe that reacted from the balanced equation. This is illustrated below:

Molar mass of Fe = 56 g/mol

Mass of Fe from the balanced equation = 1 × 56 = 56 g.

From the balanced equation above,

56 g of Fe reacted to produce –7.40 kJ of energy.

Finally, we shall determine the amount of energy produced by the reaction of

11.3 g of Fe. This is illustrated below:

From the balanced equation above,

56 g of Fe reacted to produce –7.40 kJ of energy.

Therefore, 11.3 g of Fe will react to produce = (11.3 × –7.4)/56 = –1.49 KJ of energy.

Thus, –1.49 KJ of energy are produced.