Math, asked by gaurishankarjhafbi, 9 months ago

4. Which of the following has been arranged in order of decreasing freezing
point?
(a) 0.05 M KNO3 > 0.04 M CaCl2 > 0.140 M
sugar
> 0.075 M CuSO4
(b) 0.04 M BaCl2 > 0.140 M sucrose > 0.075 M CuSO4
> 0.05 M KNO3
(c) 0.075 M CuSO4 > 0.140 M sucrose > 0.04 M BaCl2
> 0.05 M KNO3
(d) 0.075 M CuSO4 > 0.05 M NaNO3 > 0.140 M sucrose
> 0.04 M BaCl2
1-219

Answers

Answered by knjroopa

Step-by-step explanation:

Given Which of the following has been arranged in order of decreasing freezing point?

Now we need to arrange the freezing in decreasing order.
So ΔT f = kf . m.i (kf is freezing point, m is molality, I is the vector factor)
Now 0.05 M KNO3 so ΔT f depends on i
So ΔT f = m I (I = 1 + (n – 1)α) (n = no of ions and α = degree of ionisation)
So k+ and NO3- (so total will be 2)
So I = 1 + (2 – 1) 1 = 2)
= 0.05 x 2
So ΔT f = 0.10
Now for the second case we have
0.04 M Ca cl 2
So ΔT f = m. I
(so I = 1 + (n – 1) α) so Ca 2+ and 2cl – will be 3
= 1 + (3 – 1) 1
= 3)
= 0.04 x 3
= 0.12
Now for the third case we have
0.140 M sugar
So ΔT f = m x I (here I = 1) (i = (1 – 1)1 = 1)
= 0.14 x 1
= 0.14
Now for the fourth case we have
0.075 M Cu SO4 (Cu 2 + and SO4 - = 2)
So ΔT f = m x i (here I = 1 + (2 – 1) 1 = 2)
= 0.075 x 2
= 0.15
So we need to arrange, higher the freezing point, lesser ΔT f
We need to check which is lesser, so we get
0.05 M KNO3 is lesser and option 1 holds good.

Reference link will be

https://brainly.in/question/18315649

https://brainly.in/question/15570678

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