Advertisements
Advertisements
Question
Out of the following 1.0 M aqueous solution, which one will show the largest freezing point depression?
Options
NaCl
Na2SO4
C6H12O6
Al2(SO4)3
Advertisements
Solution
Al2(SO4)3
Explanation:
Freezing point depression is given by the formula;
ΔTf = i × Kb × m
Where, ΔTf = Freezing point depression
Tf = Freezing point of the solution (°C)
i = ionization or van't Hoff factor
Kf = cryoscopic constant (°C/m)
m = molality (mol/kg)
Let's check for each option one by one.
(1) \[\ce{KCl_{(aq)} <=> K^+_{ (aq)} + Cl^-_{ (aq)}}\]
total ions = 2 thus, i = 2
(2) Glucose is non-electrolyte, so it does not dissociate into ions.
\[\ce{C6H12O6 <=> no ions}\] [i = 0]
(3) \[\ce{Al2(SO4)3_{(aq)} <=> 2Al^{3+} + 3SO^{2-}_4}\]
total ions = 5 thus, i = 5
(4) \[\ce{K2SO4_{ (aq)} <=> 2K^+ + SO^{2-}_4}\]
total ions = 3 thus, i = 3
Hence, Al2(SO4)3 will exhibit the largest freezing point depression due to the highest value of i.
APPEARS IN
RELATED QUESTIONS
Calculate the depression in the freezing point of water when 10 g of CH3CH2CHClCOOH is added to 250 g of water. Ka = 1.4 × 10−3, Kf = 1.86 K kg mol−1.
A 4% solution(w/w) of sucrose (M = 342 g mol–1) in water has a freezing point of 271.15 K. Calculate the freezing point of 5% glucose (M = 180 g mol–1) in water.
(Given: Freezing point of pure water = 273.15 K)
Cryoscopic constant of a liquid is ____________.
The freezing point of equimolal aqueous solution will be highest for ____________.
Which observation(s) reflect(s) colligative properties?
(i) A 0.5 m NaBr solution has a higher vapour pressure than a 0.5 m BaCl2 solution at the same temperature.
(ii) Pure water freezes at a higher temperature than pure methanol.
(iii) A 0.1 m NaOH solution freezes at a lower temperature than pure water.
Which has the highest freezing point?
How does sprinkling of salt help in clearing the snow covered roads in hilly areas? Explain the phenomenon involved in the process.
Depression of freezing point in any dilute solution is directly proportional to ______
Of the following four aqueous solutions, total number of those solutions whose freezing points is lower than that of 0.10 M C2H5OH is ______. (Integer answer)
- 0.10 M Ba3 (PO4)2
- 0.10 M Na2 SO4
- 0.10 M KCl
- 0.10 M Li3 PO4
The depression in freezing point of water observed for the same amount of acetic acid, trichloroacetic acid and trifluoroacetic acid increases in the order given above. Explain briefly.
