Question

What is the mass in grams of NaCN in 120.0 ml of a 2.40 x 10^-5 M solution?

a. 0.072 g
b. 0.024 g
c. 0.120 g
d. 0.216 g

Answer 1

The mass of NaCN in 120.0 ml of a 2.40 x 10^-5 M solution is approximately c. 0.121 grams

Step-by-step explanation:

To calculate the mass of NaCN in the solution, we need to use the formula:

mass = volume (L) x molarity (mol/L) x molar mass (g/mol)

In this case, the volume is given as 120.0 ml, the molarity is 2.40 x 10^-5 M, and the molar mass of NaCN is 42.01 g/mol. Plugging these values into the formula:

mass = 0.120 L x 2.40 x 10^-5 mol/L x 42.01 g/mol = 0.120 x 2.40 x 10^-5 x 42.01 g = 0.120 x 1.0084 g = 0.12096 g ≈ 0.121 g

Therefore, the mass of NaCN in 120.0 ml of the solution is approximately 0.121 grams.