When P4O10(s) reacts with H2O(l) to form H3PO4(aq) , 453 kJ of energy are evolved for each mole of P4O10(s) that reacts. Write a balanced thermochemical equation for the reaction with an energy term in kJ as part of the equation.

P4O10 + 6H2O → 4H3PO4         ΔH = 453 kJ

Explanation:

A thermochemical reaction is one in which the amount of heat gained/evolved is written as part of the reaction equation.

A thermochemical equation helps us to judge whether an equation is endothermic or exothermic. For an endothermic reaction, ΔH  is positive while for an exothermic reaction ΔH is negative.

Since, the reaction of one mole of P4O10(s)  with H2O(l) to form H3PO4(aq) evolves 453 kJ of energy for each mole of P4O10(s) that reacts. Then we can write;

P4O10 + 6H2O → 4H3PO4         ΔH = 453 kJ

b. examine and describe cells