Given: BO3 + 3Mg → 3MgO + B
1. How many moles of Mg are required if 2 moles of B are produced?

6moles of Mg

Explanation:

The reaction expression is given as:

          BO₃   +    3Mg   →    3MgO    +    B

Given:

Number of moles of B produced  = 2 moles

Unknown:

Number of moles of Mg required  = ?

Solution:

  From the balanced reaction expression:

          1 mole of B is produced from 3 moles of Mg

          2 moles of B will be produced from 2 x 3  = 6moles of Mg

a. energy is absorbed in the reaction.

if in a given reaction the energy of products is greater than the energy of reactants it means that reaction is endothermic and during the reaction, the energy is absorbed by reactants. in an endothermic reaction, the products have more stored chemical energy than the reactants. and in this reaction the reactants are more stable than products before the compounds with less energy are always more stable.