Question

What would be the resulting molaritybof a solution made by dissolving 17.8 g of LiF in enough water to make a 915-millimeter solution?

Answer 1

0.751 M

Step-by-step explanation:

Given:

Mass of LiF (solute), m = 17.8 g

Volume of water (solvent), V = 915 ml = 0.915 L

Formula:

Molar mass of LiF = 25.9 g/mol

`Molarity = (moles of solute)/(Volume of solution)`

`Moles LiF= (Mass)/(Molar Mass) = (17.8 g)/(25.9 g/mol) = 0.6873 moles`

`Molarity = (0.6873 moles)/(0.915 L) = 0.751 moles/L`

Answer 2

Answer: Molarity of solution is 0.751 M.

Reason:
Given: weight of solute (LiF) = 17.8 g, volume of solution = 915 ml = 0.915 l

We know that,
Molarity =
`\frac{\text{weight of solute (g)}}{\text{Molecular weight X Volume of solution(l)}}`

Molecular Weight of LiF = 25.9 g/mol.

∴, Molarity =
`(17.8)/(25.9X0.915)`
= 0.751 M