N the following reaction: Mg(s) + 2HCl(aq) → MgCl2(aq) + H2(g) A. H2 is the reducing agent and is oxidized B. HCl is reduced and is the oxidizing agent C. MgCl2 is the oxidizing agent and is reduced D. Mg is reduced and is the oxidizing agent. E. HCl is oxidized and is the reducing agent Reset Selection

HCl is reduced and is the oxidizing agent

Explanation:

Looking at the reaction shown in the question

Mg(s) + 2HCl(aq) → MgCl2(aq) + H2(g)

HCl is reduced to H2. The oxidation number of hydrogen decreased from +1 to zero. While magnesium was oxidized. Its oxidation number increased from zero to +2.

Hence we can rightly say that HCl was the oxidizing agent since the oxidizing agent is reduced in a reaction and the reducing agent is oxidized in a reaction.

answer: the enthalpy of the overall chemical reaction is +87.88 kj or +88 kj.

according to hess's law, the overall enthalpy of a reaction is the difference between the sum of enthalpy values of all the products and the sum of enthalpy values of all the reactants.

δh(reaction) = ∑nδh(products) - ∑nδh(reactants)

δh(reaction) = [δh +δh] - [δh]

δh(reaction) = [1(-287.02) + 1(0) ] - [1(-374.9)] kj = +87.88 kj

here, δh (pcl3) = -287.02 kj, δh(cl2) = 0, δh(pcl5) = -374.9 kj

therefore, enthalpy of the overall reaction is +87.88 kj or +88 kj.