Organic hydrogenation reactions, in which h₂ and an "unsaturated" organic compound combine, are used in the food, fuel, and polymer industries. in the simplest case, ethene (c₂h₄) and h₂ form ethane (c₂h₆). if 135 kj is given off per mole of c₂h₄ reacting, how much heat is released when 14.7 kg of c₂h₆ forms?

The answer is: 6.6150 × 10⁴ kJ

Explanation:

Given reaction: C₂H₄ (ethene) + H₂ → C₂H₆ (ethane)

Given: Heat of hydrogenation of ethene = 135 kJ/mol

given mass of ethane = 14.7 kg = 14700 g    (∵ 1 kg = 1000g)

Molar mass of ethane = 30 g/mol

The number of moles of ethane = given mass ÷ molar mass = 14700 g ÷ 30 g/mol = 490 moles

As 1 mole ethene gives 1 mole ethane on hydrogenation.

Therefore, number of moles of ethane = number of moles of ethene = 490 moles

Therefore, the heat of hydrogenation for the formation of 490 moles (14.7 kg) ethane = 490 mol × 135 kJ/mol = 66150 kJ = 6.6150 × 10⁴ kJ

the answer to this question is 3.

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.