A sample of chalk (`CaCO_(3))` is contaminated with calcium sulphate 1.0 g of the solid is dissolved in 230 " mL of " `(N)/(10)` HCl, 40.1 `(N)/(10)` NaOH is requried to neutralise the excess acid. What ist he percentage of chalk in the mixture.

A sample of 3.95g of 60% pure chalk (impurities in the chalk are insoluble in HCl), is dissolved in 250 mL of 0.2(M) HCl. What volume (cm^(3)) of 0.01 (N) NaOH is required to neutralise the excess acid?

1.725 g of a metal carbonate is mixed with 300 mL of N/10 HCI. 10 mL of N/2 sodium hydroxide were required to neutralise excess of the acid. Calculate the equivalent mass of the metal carbonate.

A sample of sodium carbonate contains impurity of sodium sulphate. 1.25 g of this sample are dissolved in water and volume made up to 250 mL. 25 mL of this solution neutralise 20 mL of N/10 sulphuric acid. Calculate the percentage of sodium carbonate in the sample.

The pH of the solution obtained by mixing 10 mL of 10^-1 N HCl and 10 mL of 10^-1 N NaOH is:

150 mL of N//10 HCl is required to react completely with 1.0 g of a sample of limestone. Calculate the percentage purity of calcium carbonate.

The volume (in mL) of 0.1 N NaOH required to neutralise 10 mL of 0.1 N phosphinic acid is _________