During a practical lesson, solution X was prepared by dissolving Y g of a mixture of sodium carbonate and sodium hydrogen carbonate in enough distilled water and made up to 500 ml of solution. About 2

I will solve question 37.

37. During a practical lesson, solution X was prepared by dissolving Y g of a mixture of sodium carbonate and sodium hydrogen carbonate in enough distilled water and made up to 500 ml of solution. About 25 cm$^3$ of the solution mixture was titrated with hydrochloric acid of molarity 0.1 M. First using phenolphthalein followed by screened methyl orange as indicators.

*(i) The first step of the titration using phenolphthalein indicator required 25.0 cm$^3$ of the acid for the colour to be discharged and the equation for the reaction is: $\text{Na}_2CO_3(aq) + \text