Can someone tell me how to find moles in acid&base equations (simple explination pls)

When the base neutralizes the acid, the number of moles of H+ = the number of moles of OH-. Therefore, the number of moles of H+ = 0.0125 moles. Every mole of HCl will produce one mole of H+; therefore, the number of moles of HCl = number of moles of H+. The concentration of the HCl is 0.25 M

1.solid

2.carbon dioxide

3.helium

you didnt put any of the following