Na2O + HCl→ NaCl +H2O
Does the equation above satisfy the law of mass conservation of matter.
No, since there are two sodium atoms as reactants, but only one sodium atom as a product.
Step-by-step explanation
According to the law of mass conservation the number of atoms in the reactant side must be equal to the number of atoms in the product side.
For this reason the equation above does not satisfy the law of mass conservation since the number of sodium atoms are not equal in both side.