a 36 grams sample of calcium hydroxide is allowed to react with 40.5 grams of phosphoric acid according to the following reaction.
Interesting but I don't see a question.
To fully answer your question, you need to provide the balanced chemical equation for the reaction between calcium hydroxide and phosphoric acid. This equation will allow us to determine the stoichiometry of the reaction, which will ultimately help us in answering your question.
Once you provide the balanced chemical equation, I will be able to assist you further.