Question

What is the molarity of solution if 20.0 g of naoh are dissolved in 1000 ml of solution?

a. 1.00 m
b. 2.00 m
c. 2.50 m
d. 0.50 m

Answer 1

The molarity of a solution made by dissolving 20.0 g of NaOH in 1000 ml of solution is 0.50 M, as calculated by dividing the number of moles of NaOH (0.5 mol) by the volume of the solution in liters (1.0 L). The correct answer is d. 0.50 m.

Step-by-step explanation:

To calculate the molarity of a solution, we need to know two things: the number of moles of solute and the volume of the solution in liters. The molar mass of sodium hydroxide (NaOH) is 40.0 g/mol, so to find the number of moles of NaOH in 20.0 g, we divide the mass by the molar mass.

Number of moles of NaOH = 20.0 g / 40.0 g/mol = 0.5 mol NaOH

Since the volume of the solution is 1000 ml, which is equivalent to 1.0 L, we can then calculate the molarity using the formula:

Molarity (M) = moles of solute / liters of solution

Molarity of NaOH = 0.5 mol / 1.0 L = 0.50 M

Therefore, the molarity of the solution is 0.50 M, which corresponds to option d. 0.50 M.