1. In an experiment, 0.933 g of a sample of washing soda (Na2CO3. xH2O) wasdissolved in some distilled water. The solution was treated against 0.258 Mhydrochloric acid. 25.4 cm3 of the acid was required for the completion of thefollowing reaction:Na2CO3 + 2HCl → 2NaCl + H2O + CO2i. From the result, calculate the number of moles of sodium carbonate in thesample of washing soda

To calculate the number of moles of sodium carbonate in the sample of washing soda, we need to use the given information.

1. First, we need to find the number of moles of hydrochloric acid used in the reaction. We can use the formula:

   Moles of acid = Volume of acid (in liters) x Concentration of acid (in moles per liter)

   Given that the volume of acid used is 25.4 cm3 (which is equivalent to 0.0254 liters) and the concentration of the acid is 0.258 M, we can calculate the moles of acid:

   Moles of acid = 0.0254 L x 0.258 mol/L = 0.0065612 mol

2. According to the balanced chemical equation, the ratio between hydrochloric acid and sodium carbonate is 2:1. This means that for every 2 moles of hydrochloric acid, 1 mole of sodium carbonate is consumed.

   Therefore, the number of moles of sodium carbonate can be calculated using the ratio:

   Moles of sodium carbonate = 0.0065612 mol x (1 mol sodium carbonate / 2 mol hydrochloric acid) = 0.0032806 mol

3. Finally, we can convert the mass of sodium carbonate to moles using the molar mass of sodium carbonate. The molar mass of Na2CO3 is 105.99 g/mol.

   Moles of sodium carbonate = Mass of sodium carbonate (in grams) / Molar mass of sodium carbonate

   Given that the mass of the sample of washing soda is 0.933 g, we can calculate the moles of sodium carbonate:

   Moles of sodium carbonate = 0.933 g / 105.99 g/mol = 0.008791 mol

Therefore, the number of moles of sodium carbonate in the sample of washing soda is approximately 0.008791 mol.