The substance(s) to the left of the arrow in a chemical equation are called reactants. A reactant is a substance that is present at the start of a chemical reaction. ... A product is a substance that is present at the end of a chemical reaction.

✓ Reactants

✓Reactants

✓ product

Explanation:

The substance(s) to the left of the arrow in a chemical equation are called

A is a substance that is present at the start of a chemical reaction.

A is a substance that is present at the end of a chemical reaction.

Reactants are substances that undergo chemical reaction and are present at the beginning of the reaction and are consumed during the process of the reaction to form a product.

2H2 + O2 >2H2O

Here H2 and O2 are Reactants while water H2O is the product ( water)

Products are species that are produced after the chemical reaction have taken place.

"standard molar enthalpy:

h2o ( liquid water ) : - 285.8 kj/mole

h2o ( water vapor ) : - 241.8 kj / mole.

δhrxn = - 241. 8 - ( - 285.8 )= -241.8 + 285.8 = 44.0

answer: 44.0 kj"

the product of the pressure and volume is also constant