Question

When c2h4(g) reacts with h2o(g) to form ch3ch2oh(g) , 45.6 kj of energy are evolved for each mole of c2h4(g) that reacts. write a balanced thermochemical equation for the reaction with an energy term in kj as part of the equation. note that the answer box for the energy term is case sensitive. use the smallest integer coefficients possible and put the energy term (including the units) in the last box on the appropriate side of the equation. if a box is not needed, leave it blank. + + +?

Answer 1

As given, it is an exothermic reaction, there is release of energy, so we will write the energy on product side.

The balanced equation of reaction of ethene with water will be:

`C_(2)H_(4) (g)  + H_(2)O (g)   --->  CH_(3)CH_(2)OH (g)`

Now as we have to write a thermochemical equation we will write it as

`C_(2)H_(4) (g)  + H_(2)O (g)   --->  CH_(3)CH_(2)OH (g) + 45.6 kJ`

So when we have to write a balanced equation:

a) we should write all the compounds present in reactant side followed by product side

b) we balance all the elements on both the side

c) based on type of reaction we put energy on reactant / product side