# 14 - Solutions Questions Answers

Q.WRITE CELL RECTION OF THE FOLLOWING- .{1} ZN | ZN2+ || cu2+ |cu    {2}    PT {H2} | HCL || CL2{PT}

Joshi sir comment

Zn                  ----------->   Zn++   +   2e-

Cu++ + 2e-   ----------->   Cu

H2  -------->  2H+  +   2e

Cl+ 2e-      -------->  2Cl-

one molar solution of sulphuric acid is equal to  2N. how???

sir  as we know for sul.acid n factor = 2

so  normality will be = 2xM  thus M = N/2

but ans is 2N so plz give account of it .

Joshi sir comment

molarity = 1

and N = nM = 2(1) = 2

hence it is clear

Chemistry >> Physical Chemistry >> Solutions Engineering Exam

q. = Mass of solution of 1 molal glucose solution to get 0.2 molal glucose is.

a.200

b.300

c.236

d.108

Joshi sir comment

I think question is incomplete, correct it first

acetic acid in a solvent undergoes 20% dissociation and 70% association, find vant hoff factor.

Joshi sir comment

CH3COOH  = CH3COO- + H+

1                     0                 0

0.8                 0.2               0.2

CH3COO- + H+ = CH3COOH

0.2             0.2               0.8

0.06            0.06           0.8+0.14

0.06             0.06              0.94                      sum = 1.06

so i = 1.06/1 = 1.06

calculate the molecular weight of cellulose acetate if its 0.2%wt/vol solution in acetone(sp. gravity 0.8) shows osmotic rise of 23.1mm against pure acetone at 27C.

Joshi sir comment

By formula πV = nRT

π = hdg, n=w/M

given

0.2%wt/vol solution in acetone means w= 0.2 gm, V = 100 ml= 100/1000 litre = 0.1*10-3 m3 ,   h = 23.1/1000 m, d = 800 kg/m3 ,

now solve

Why gas in gas not a solution
Asked By: JASEEM A RAHMAN P
Joshi sir comment

gas in gas is a solution but interaction between the molecules play almost no role so these solutions are addressed as mixtures

WHAT OSMOTIC PRESSURE WOULD BE OF 1.25m SUCROSE SOLUTION AT 25C ?DENSITY OF SOLUTION IS 1.34g/mL?

Joshi sir comment

formula is πV = nRT or π = MRT,   M is molarity

strength of solution is 1.25m

so 1000 gm water ..............................................1.25 mole sucrose

so 1000 gm water .............................................1.25*342=427.5gm sucrose

so 1427.5 gm solution ....................................1.25 mole sucrose

so 1427.5/1.34=1065.30 ml = 1.0653 L solution ...........................1.25 mole sucrose

so M = 1.25/1.0653

put all the values to get answer.

THE PRESSURE OF ATMOSPHERE AIR IS 720 mm  . THE PRESSURE OF WATER VAPOUR IN THE AIR IS

A) 5.55

B) 21

C) 18

D) ZERO

Joshi sir comment

In this question atmospheric pressure should be given then

P0 - 720 mm will be the answer.

what will be the conc of nitrate ion when 400ml of 0.1 M AgNO3 is mixed with 100 ml of 0.2 m BaBr2

Joshi sir comment

no. of miligm. eq. of AgNO= 400*0.1 = 40

no. of miligm. eq. of BaBr2 = 100*0.2*2 = 40

so no of miligm. eq. of Ba(NO3)= 40 so no. of milimoles of Ba(NO3)2 = 20

so [NO3-] = 20*2/500 = .08 M

WHICH OF THE FOLLOWING HAS LOWEST BOILING PT.  (HARY. PMT 2003)

1)  NaCl

2) CuCl

3)  CuCI2

4) CsCl

SIR ANSWER GIVEN IS(3)  . BUT AS THE NO. OF IONS IS MAX IN CuCl2 SO IT SHOULD HAVE MAX BP . THEN WHY ITS BP WILL BE MIN. ??