Question

78.3 g of magnesium fluoride (MgF2) is dissolved in 9.4 kg of water. What is the molality?

Answer 1

Hope this helps.....

Answer 2

Given:-

→ Mass of Magnesium Fluoride

[solute] = 78.3g

→ Mass of water [solvent] = 9.4kg

To find:-

→ Molality of the solution

Solution:-

• Molar mass of Magnesium = 24g/mol

• Molar mass of Fluorine = 19g/mol

Hence, molar mass of MgF₂ :-

= 24 + 19×2

= 24 + 38

= 62g/mol

Number of mole in 78.3g MgF₂ :-

= Given Mass/Molar mass

= 78.3/62

= 1.26 mole

Molality of a solution :-

= Moles of solute/Mass of solvent [kg]

= 1.26/9.4

= 0.134 m

Thus, molality of the solution

is 0.134 m .

Some Extra Information:-

• Molarity of a solution:-

Moles of solute/Vol. of solution (L)

• Normality of a solution :-

G-equivalents of solute/Vol.of solution(L)