Question

A 32.0-g sample of HF is dissolved in water to give 2.0 × 102 mL of solution. The concentration of the solution is:

Answer 1

The concentration of the solution is 8 M

calculation

Concentration = moles/volume in liters

step 1: find moles of HF

moles of HF =mass/molar mass

molar mass of HF = 1+ 19 )= 20 g/mol

moles is therefore = 32.0 g/ 20 g/mol= 1.6 moles

Step 2: convert ml to L

volume in liters = 2.0 x 10^2 / 1000 =0.2 l

step 3: find the concentration

concentration = 1.6 mol / 0.2 l = 8 M