Chemistry; solutions

Question

An experiment calls for 50 mL of a 0.5 M aqueous solution of sodium hydrogen carbonate. Describe how you would make up such a solution?

Answer 1

Sodium hydrogen carbonate is NaHCO3, also known as sodium bicarbonate.

0.5 M means 0.5 moles/liter

To make 50 ml, that is equivalent to 0.050 liters, so you will need 0.5 moles/L x 0.05 L = 0.025 moles NaHCO3

Molar mass NaHCO3 = 84.0 g/mole

Thus to make 50 ml (0.050 L) of 0.5 M NaHCO3 you need 0.025 moles x 84.0 g/mole = 2.1 grams

Weigh out 2.1 grams NaHCO3 and dissolve in enough water to make a final volume of 50 ml.