Chemistry

A 0.500 g mixture of sodium hydroxide and sodium carbonate was in distilled water and 25 ml of the solution required 21.00 ml of 0.100 M hydrochloric acid,HCL(aq) to reach endpoint using phenolphthalein indicator solution. The remaining mixture required 7.85 ml of 0.100 M HCL(aq) to reach the endpoint using methyl orange indicator.
i. Calculate the concentration of sodium hydroxide, NaOH(aq) and sodium carbonate, Na2CO3 in the mixture.
ii. Determine the percentage of sodium hydroxide in the mixture