Sodium carbonate exists in hydrated form, Na2CO3.xH2O, in the solid state. 3.5 g of a sodium carbonate sample was dissolved in water and the volume made up to 250 cm3. 25.0 cm3 of this solution was titrated against 0.1 moldm-3 HCl and 24.5 cm3 of the acid were required. Calculate the value of x given the equation:
Sodium carbonate exists in hydrated form, Na2CO3.xH2O, in the solid state. 3.5 g of a sodium carbonate sample was dissolved in water and the volume made up to 250 cm3. 25.0 cm3 of this solution was titrated against 0.1 moldm-3 HCl and 24.5 cm3 of the acid were required. Calculate the value of x given the equation:
Na2CO3 + 2HCl à 2NaCl + CO2 + H2O
find moles of HCl using concentration and volume given divide this by 2 to find moles in Na2CO3 multiply this by 10 to find moles in original solution use number of moles and mass (3.5g) to find relative formula mass of hydrated sodium carbonate take away relative formula mass of Na2CO3 only divide this by 18 and round if necessary to give x