How many grams of solid K2CO3 are needed to prepare 150. mL of a 0.50% by volume K2CO3 solution?

0.75 g of K2CO3

Explanation:

To prepare 150. mL of a 0.50% by volume K2CO3 solution; It means 0.5% w/v in 150 mL. Therefore, there would be 0.5 of K2CO3 in 100 mL of the solution. Taking the density of the solution to be equivalent to the density of water, that is, 1 g/ml. The mass of the solution will be; 150 mL * 1 g/mL = 150 g

Therefore; the mass of K2CO3 will be;

= 0.5/100 * 150 g

= 0.75 g