Question

From the solution 1% Na2CO3 ,prepare 0.05 N ,and 0.02 N solution in 250ml solutiom

Answer 1

Explanation:

A standard solution is a solution whose concentration has been accurately determined. Standard solutions are prepared from highly pure chemicals and the exact concentration is determined by a process called standardization. The substance available for standardization of a solution is highly pure is called a primary standard.

Aim

To prepare the 250 cm3 of N/10 standard solution of sodium carbonate.

Theory

Sodium carbonate is essentially insoluble in nearly saturated sodium hydroxide. The insoluble sodium carbonate will settle to the bottom of the container after the saturated NaOH has equilibrated for a couple of days. The supernatant can be withdrawn carefully to prepare diluted NaOH solution free of sodium carbonate. The water for preparing NaOH standard solution should be boiled to remove any dissolved CO2, because dissolved CO2 can cause a titration error.