which is a stronger electrolyte?

Question

can someone show me how to use the data to solve this problem? Thank you so much.

When 10.0 g of mercuric nitrate, Hg(NO3)2 is dissolved in 1.00 kg of water, the freezing point of the solution is -0.162 C. When 10.0 g of mercuric chloride, HgCl2 is dissolved in 1.00 kg of water, the solution freezes at -0.0685 C. Use these data to determine which is the stronger electrolyte, Hg(NO3)2 or HgCl2.

Answer 1

Depression in freezing point is related to molecular weight and molal depression constant by the equation

To-Tf = DT = Kf x w2/M x 1000/w1 where

To is the freezing point of pure solvent.
Tf is the freezing point of solution
DT is the difference or depression in freezing point.
Kf is the molal depression constant of the solvent.
w2 is the weight of solute,
M is the molecular weight of the solute and
w1 is the weight of solvent.

Molecular weight of Hg(NO3)2 is 324 and that of Hg Cl2 is 271.

Substituting the values for Hg (NO3)2 we get

0.162 = Kf (merc nit} x 10/324 x 1000/1000.
Kf (merc nit) = 0.162 x 324/10 x 1000/1000 = 5.25

and for Hg(Cl)2 we get

0.0685 = Kf (merc chlo) x 10/271 x 1000/1000
Kf (merc chlo) = 0.0685 x 271/10 x 1000/1000 = 1.86

It is seen that Kf for mercuric nitrate solution is high (almost three times) than that for a mercuric chloride solution. This is abnormal as mercuric nitrate has a higher molecular weight than mercuric chloride.

Molal depression constant of the solvent can only be constant. Hence the change in values could have come only due to solutes. Value of any colligative property depends on the number of particles of the solute. It is possible for the theoretical values to be less than the measured values if the solute dissociates.

(It is to be noted that the reverse is also possible if the molecules of the solute associate eg : acetic acid forming hydrogen bonds)

This could be the only reason for the abnormal values for Kf for mercuric nitrate and mercuric chloride solution.

We conclude that in the above experiment a higher value for mercuric nitrate is due to the fact that its molality has somehow become higher. This in turn is possible (inspite of higher molecular weight for mercuric nitrate) only if it has dissociated more. Hence Mercuric Nitrate is a stronger electrolyte than Mercuric Chloride.

Answer 2

It goes something like this: Hg(NO3)2 is the stronger electrolyte. The reason is that Hg(NO3)2 is more completely ionized into Hg2+ + 2NO3- than is HgCl2 into Hg2+ + 2Cl-. This means that Hg(NO3)2 is ionized into three moles of ions, Hg2+ + NO3- + NO3-, whereas HgCl2 is incompletely ionized into about "two-and-a-half" ions. That means that the solution whose electrolyte contributes more moles of ions per kilogram of solvent will depress the freezing point of the solution more.

Atomic weights: Hg = 200 (okay, I know it's 200.6) N = 14, O = 16, Cl = 35.5. Hg(NO3)2 = 324, HgCl2 = 271. Let HgN = Hg(NO3)2, let HgC = HgCl2

10gHgN/1KgH2O x 1molHgN/324gHgN = 10/324 = 3.1 x 10^-1 molHgN/1KgSolvent =3.1x10^-1molal

10gHgC x 1molHgC/271gHgC = 3.7 x 10^-1molHgC/1kgSolvent = 3.7x10^-1 molal

So you see that the HgCl2 solution has the greater molality (3.7x10^-1 versus 3.1x10^-1), yet its solution freezes at a higher temperature (-0.07C versus --0.16C) than Hg(NO3)2 solution that has lower molality.

Answer 3

a good electrolyte is a answer which could habit electrical energy o.k.. A vulnerable electrolyte is a answer which could habit electrical energy, yet no longer besides as a good electrolyte can. And a nonelectrolyte won't be ready to behaviour electrical energy in any respect.

Answer 4

Freezing point depression is a colligative property meaning that it depends upon the number of particles in solution. The fact that the mercury (II) nitrate depressed the freezing point more that the mercury (II) chloride means there are more dissolved ions in the mercury (II) nitrate solution. The strength of an electrolyte is dependent on the concentration of ions. So the mercury (II) nitrate is the stronger electrolyte.

I think there is one error in the question. 10 g of mercury (II) chloride will not dissolve in 100 g of water. Of course that is the reason it is a poorer electrolyte than the mercury (II) nitrate; it is not as soluble.

Answer 5

Hg(No3)2 causes more depression in boiling point so it produces more ions than hgcl2. So Hg(no3)2 is stronger electrolyte.