a) 1.20 dm3 of hydrogen chloride gas was dissolved in 100 cm 3 of water. i) Calculate the number of moles of hydrogen chloride gas present. ii) Calculate the concentration of the hydrochloric acid formed. b) 25.0 cm3 of the acid was then titrated against sodium hydroxide of concentration 0.200 mol dm3 to form NaCl and water: NaOH + HCl H2O + NaCl i) Calculate the number of moles of acid used. ii) Calculate the volume of sodium hydroxide used.