Question

20 grams of hydrogen fluoride gas, HF, is dissolved in 0.5 liters of solution. Determine the molarity (M).

Answer 1

To determine the molarity of the HF solution, divide the number of moles of HF (calculated as 1 mole from 20 grams) by the volume of the solution (0.5 liters), which results in a molarity of 2 M.

Step-by-step explanation:

To determine the molarity of the hydrogen fluoride (HF) solution, we need to calculate the number of moles of HF and divide that by the volume of the solution in liters. The molar mass of HF is approximately 20.01 g/mol (1 H atom = 1.01 g/mol + 1 F atom = 19.00 g/mol).

First, we calculate the number of moles: 20 grams HF / 20.01 g/mol = ~1 mole HF.

Since the solution volume is 0.5 liters, we can calculate the molarity (M) as follows:

Molarity (M) = moles of solute / liters of solution = 1 mole HF / 0.5 L solution = 2 M.

Therefore, the solution is 2 Molar (2 M).