The oxide that gives hydrogen peroxide on treatment with a dilute acid is

Molecular formula of Glauber's salt is:

Write down the balanced equations for the reaction when:
Calcium phosphate is heated with a mixture of sand and carbon;

$$P\left( {A \cup B} \right) = P\left( {A \cap B} \right)$$ if and only if the relation between $$P(A)$$ and $$P(B)$$ is .............