Home
Class 11
CHEMISTRY
For a perfectly cyrstalline solid C(p,m)...

For a perfectly cyrstalline solid `C_(p,m)= a T^(3) + bT`, where a and b are constants. If `C_(p,m)` is 0.40 J/K mol at 10K and 0.92 J/K mol at 20K, then molar entropy at 20K is `0.2x xx R` joules. Then the value of x is

A

`0.92` J/K mol

B

`8.66` J/K mol

C

`0.813` J/K mol

D

None of these

Text Solution

Verified by Experts

The correct Answer is:
C
`0.40=aT_(1)^(3)+bT_(1)`
`0.40xxa(1000)+bxx10`
`0.4=1000a+10b` …(1)
`0.92=aT_(2)^(3)+bT_(2)`
`rArr" "0.92=axx8000+20b` …(2)
from Eqs. (1) and (2)
`a = 2xx10^(-5)," "b=0.038`
`S_(m)=int(aT^(3)+bT)/(T).dT`
`=(a[T_(2)^(3)-T_(1)^(3)])/(3)+b[T_(2)-T_(1)]`
`0.813"J/K-mol"`
Promotional Banner

Topper's Solved these Questions

  • THERMODYNAMICS

    NARENDRA AWASTHI|Exercise Level 1 (Q.1 To Q.30)|6 Videos

  • THERMODYNAMICS

    NARENDRA AWASTHI|Exercise Level 1 (Q.31 To Q.60)|2 Videos

  • STOICHIOMETRY

    NARENDRA AWASTHI|Exercise Level 3 - Subjective Problems|20 Videos

Similar Questions

Explore conceptually related problems

For a perfectly crystalline solid C_(p.m) = aT^(3) , where a is constant. If C_(p.m) is 0.42 J/K - mol at 10K, molar entropy at 10K is

What is the value of gas constant R in J mol^(-1 ) K^(-1) ?

The molar specific heat of a gas at constant volume is 20 Joule/gm mol/K. The value of gamma for it will be

let a be unit vector, b = 2i + j - k and c = I + 3k. The maximum value of [a b c] is

If a = 2i + 3j - 5k, b = mi + nj + 12k and a xx b = 0 then (m, n) =

For a reaction, A_(2) + B_(2) hArr 2AB, DeltaG and DeltaS values are 20 kJ/mol and -20 J/K/mol respectively at 200k. DeltaC_(P) " is " 20 JK^(-1) . Then identify the correct property of the reaction.

The elevation in boiling point of a solution containing 0.20g of solute in 20g of ether is 0.17^@C , K_b for ether is 2.16 K kg/mol. Calculate the molar mass of solute.