Two different samples of sodium carbonate are contaminated with sodium hydrogencarbonate and sodium hydroxide respectively.
(a) 20.0㎤ of a solution containing sodium hydroxide and sodium carbonate required 19.20㎤ of 0.500mol dm-3 HCl with phenolphthalein as indicator, forming sodium hydrogencarbonate in the process. With methyl orange, a further 5.10㎤ of the acid was needed to complete the neutralisation of sodium hydrogencarbonate into carbon dioxide and water.
(i) Construct 3 balanced chemical equations for the reactions that occured in the experiment.
(ii) Calculate the concentration of each compound in the original solution.
here's what i did for part (a) (i), the three balanced chemical equations i came up with are
1. Na2CO3 + 2HCl -> 2NaCl +CO2 + H2O
2. NaOH + HCl -> NaCl + H2O
3. NaHCO3 + HCl -> NaCl + H2O + CO2
I need to know if these equations are right, so as to continue attempting the second part of the question .
Also, I don't quite understand how sodium hydroxide, sodium carbonate and HCl forms sodium hydrogencarbonate...