Question

What is 4.2 moles of lithium fluoride are dissolved in 200 lliliters of solution in molarity?

Answer 1

In this question we have to find the molarity of lithium floride (LiF)

This can be calculated by formula

Molarity=moles of solute/liters of solution

In given data

Mole of solute=4.2mole of LiF

Liter of solution= 200mL=200/1000=0.2liter

M=4.2/0.2=21M solution of lithium fluoride

Answer 2

21 mol·L⁻¹

Step-by-step explanation:

Data:

n = 4.2 mol

V = 200 mL

Calculation:

c = moles/litres = n/V

V = 200 mL Convert to litres

V = 200 mL ×(1 L/1000 mL)

V = 0.200 L

c = 4.2/0.200

c = 21 mol·L⁻¹

Note: This is an impossible value. Even at 100 °C, the solubility of NaF is only about 2 mol·L⁻¹.