Grade 12Mechanics
What is the freezing point of an aqueous solution that was at 104°C?
1 Answer
Kuldip Pawar
use equation for boiling point elevation ∆Tb = Kb x m x i .and this equation for freezing point depression ∆Tf = Kf x m x i .Kb = ebullioscopic constant (aka boiling point elevation constant) for the solvent (water in this case) = 0.512 C/m .Kf = cryoscopic constant (aka freezing point depression constant) for the solvent. = 1.86 C / m for water .m = molality of the solution = moles solute / kg solvent .i = van`t hoff factor = # ions produced in solution / molecule solvent .got that?... the idea here is m and i are constant for the solution. the concentration doesn`t change. neither does the amount of ions in solution. so from the equations above... ∆Tb / Kb = m x i = ∆Tf / Kf .rearranging ∆Tf = ∆Tb x Kf / Kb .since the normal boiling point of water = 100C .∆Tf = (104 C - 100 C) x (1.86 C/m) / (0.512 C/m) = 14.53 C .since the normal freezing point of water = 0C and ∆Tf = 14.53 C, the depressed freezing point = -14.53 C
Other Related Questions on mechanics
Three identical balls are placed on a frictionless
horizontal surface touching each other. They stick to
each other because of adhesive. Another ball of same
radius and mass m is placed over the void created by
the three balls. Find the forces applied by the balls
kept on the floor to each other if the system remains
in equilibrium.
Three identical balls are placed on a frictionless
horizontal surface touching each other. They stick to
each other because of adhesive. Another ball of same
radius and mass m is placed over the void created by
the three balls. Find the forces applied by the balls
kept on the floor to each other if the system remains
in equilibrium.
mechanics
Last Activity: 9 Months ago
A car loaded with water having total mass 1000 kg moves on a straight horizontal Road starting from rest under the action of a force of 100 Newton. The water spills throw a small hole in the bottom at a rate of 0.1 KG per second the velocity of cart after 300 seconds is nearly.
11
21
31
41
A car loaded with water having total mass 1000 kg moves on a straight horizontal Road starting from rest under the action of a force of 100 Newton. The water spills throw a small hole in the bottom at a rate of 0.1 KG per second the velocity of cart after 300 seconds is nearly.
11
21
31
41
mechanics
Last Activity: 10 Months ago
A metal strip clamped at one end vibrates with a frequency of 20 Hz and amplitude of 5 mmat the free end, where a small mass of 2 g is positioned. determine(i) The velocity of the end when passing through the zero position(ii) The acceleration at maximum displacement(iii) The maximum kinetic energy of the mass
A metal strip clamped at one end vibrates with a frequency of 20 Hz and amplitude of 5 mm
at the free end, where a small mass of 2 g is positioned. determine
(i) The velocity of the end when passing through the zero position
(ii) The acceleration at maximum displacement
(iii) The maximum kinetic energy of the mass
mechanics
Last Activity: 3 Years ago
If a=x² find the displacement at t =3sec if body velocity at t= 0 sec is 0
If a=x² find the displacement at t =3sec if body velocity at t= 0 sec is 0
mechanics
Last Activity: 3 Years ago