The incorrect statement(s) regarding 2M MgCl2 aqueous solution is/are (d solution = 1.09gm/ml)
(A) Molality of Cl is 4.44m
(B) Mole fraction of MgCl2 is exactly 0.035
(C) The conc.of MgCl2 is 19%w/v
(D) The conc.of MgCl2 is 19*10⁴ ppm
Answers
it has given that 2M MgCl₂ aqueous solution where density of solution is 1.09 g/ml.
To check : The incorrect statement (s) is/ are ..
A) Molality of Cl is 4.44m
B) Mole fraction of MgCl₂ is exactly 0.035
C) The conc. of MgCl₂ is 19% w/v
D) The conc. of MgCl₂ is 19 × 10⁴ ppm
solution : molarity of MgCl₂ = 2M , it means 2 moles of MgCl₂ present in 1 Litre of solution.
mass of solution = 1000 ml × 1.09 g/ml
= 1090 g
Molality of MgCl₂ = no of moles of MgCl₂/mass of solvent in kg
= 2 × 1000/1090
= 2000/1090
= 1.83486 molal
Molality of Cl = 2 × molality of MgCl₂
= 2 × 1.83486 = 3.66972 m
so option (A) is incorrect.
mass of solute = 2 moles × (24 + 71) g/mol
= 2 × 95 = 190 g
mass of solvent = 1090 - 190 = 900 g
no of moles of solvent = 900/18 = 50
mole fraction of MgCl₂ = 2/(2 +50) = 0.0386
option (B) is also incorrect.
conc. of MgCl₂ w/v = 190/1000 × 100
= 19 %
option (B) is correct.
conc. of MgCl₂ in ppm = mass of solute/mass of solution × 10⁶
= 190/1090 × 10⁶
= 0.1743 × 10⁶ ppm
= 17.43 × 10⁴ ppm
option (D) is incorrect.
Therefore options (A), (B) and (D) are correct.
Answer:
Explanation:
This is the correct solution 100%
