1. The problem statement, all variables and given/known data 0.7g of Na2CO3.xH2O were dissolved in water and the volume was made to 100 ml, 20 ml of this solution required 19.8 ml of N/10 HCl for complete neutralization. The value of x ? 2. Relevant equations Na2CO3 + 2HCl = 2NaCl + H2O + CO2 3. The attempt at a solution I have taken the Normality of sodium carbonate solution as 0.07 N. Since the solution is dissolved in water and not in any other solution, the number of molecules of water in sodium carbonate should not matter for calculating the normality of the solution. This requires 19.8 ml of 0.1 N HCl. I have tried balancing the equivalents, i.e the equivalent of sodium carbonate is Normality x volume = 0.07 * 20 = 0.14. The equivalents of HCl is 0.1 * 19.8 = 1.98. Where does the "x" come in ?