Question

CALCULLATE THE APPROXIMATELY B.P OF A SOLUTION OF 285gm OF MAGENSIUM CHLORIDE IN 2KG OF WATER

Answer 1

Answer:

375.304 K.

Explanation:

To answer this question we need to know the Ebullioscopic constant(Kb) of water which is 0.512(°K·kg)/mol.

Since Magnesium chloride is added to water there will be elevation in boiling point of water.

It is given by

ΔTb=kb.m ( here ΔTb is elevation in boiling point, m is molality of that solution).

Elevation in boiling point is a colligative property which means it depends on number of particles in given solution. In case of magnesium chloride, which is a strong is electrolyte, 3 particles( one magnesium ion and two chloride ions) are present instead of one for one atom. So the term kb.m must be multiplied by a factor of three ( Vant Hoff's factor).

Let us calculate molality

m = 285/95 x 1/2

m=1.5 mol/Kg

Let the B.P of the solution be T.

Therefore elevation in B.P is (T-373) K (since B.P of water is 373 K)

Hence, T - 373 = 3 x 1.5 x 0.512

T=373+2.304

Hence boiling point of that solution is 375.304 K.

Mission accomplished....