Question

What mass in g of NaCl is required to prepare 250.0 mL of a 0.3210 M NaCl solution? mass NaCl: Answer g Describe how to prepare this solution using a 250.0 mL volumetric flask by placing the steps in the correct order. Not all of the steps will be used.

Answer 1

Explanation:

Molarity = 0.3210M

Volume = 250ml

Mass = ?

Molarity is defined as the number of moles of solute per liter of solution. It's unit is mol/L.

This means 0.3210 solution contains  0.3210 moles of sodium chloride in 1.0 L of solution.

The target solution has a volume of 250ml. Upon conversion to L by dividing by 1000 we have;

250 / 1000 = 0.250L

if 0.3210 moles = 1L

0.250 = x

x = 0.250 * 1 / 0.3210

x = 0.7788 moles

Sodium chloride has a molar mass of 58.44 g mol−1, which basically means that one mole of sodium chloride has a mass of 58.44 g.

1 mole = 58.44g

0.7788 mole = x

9

x = 0.7788 * 58.44 / 1

x = 45.51g

To prepare 0.3210 M NaCl; dissolve (45.51g / 4 = 11.3775g) of Nacl in (1 L / 4 = 250ml) of water.