Question

What is the molarity of a 2.4-liter solution containing 124 grams of HF?

a. 2.6 M HF <----- my guess based on calculations
b. 6.2 M HF
c. 8.3 M HF
d. 15 M HF

Answer 1

The Answer is A as you said:

Molarity =
`(no. of moles)/(volume)`

moles of HF =
`(mass)/(molar mass)`
=
`(124)/((1 + 19))`
= 6.2 mol

∴ molarity of HF =
`(6.2 mol)/(2.4 dm^(3) )`
= 2.58 M
≈ 2.6 M

Answer 2

Molar mass:

HF = 1 + 19 = 20.0 g/mol

Number of moles :

124 / 20.0 => 6.2 moles

Volume = 2.4 L

M = n / V

M = 6.2 / 2.4

M = 2.6 M

Answer A

hope this helps!