I need answers plz
btw D says ice crystals

B. Hydrogen and oxygen molecules

General Formulas and Concepts:

Chemistry - Reactions

Explanation:

Step 1: Define

Reaction RxN:   2H₂ + O₂ → 2H₂O

Step 2: Identify

Reactants:   H₂ and O₂

Products: H₂O

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.

the answer would be a