Question

Calculate the molarity of the two solutions.
a). The first solution contains 0.550 mol of NaOH in 2.50 L of solution.

b). The second solution contains 15.7 g of NaCl in 709 mL of solution.

Answer 1

Answer:

A = Molarity = 0.22 M

B = Molarity = 0.36 M

Explanation:

Given data:

For first solution:

number of moles = 0.550 mol

Volume of solution = 2.50 L

Molarity = ?

Molarity:

Formula:

Molarity = number of moles of solute / volume of solution in L.

Molarity = 0.550 mol / 2.50 L

Molarity = 0.22 M

For second solution:

Mass of NaCl =  15.7 g

Volume of solution = 709 mL  or 709/1000 = 0.709 L

Molarity = ?

Solution:

Number of moles = mass / molar mass

Number of moles = 14.7 g/ 58.44 g/mol

Number of moles = 0.252 mol

Molarity:

Molarity = number of moles of solute / volume of solution in L.

Molarity = 0.252 mol / 0.709 L

Molarity = 0.36 M