481Hmmmmm.....gt it..
1.SN1,SN2,E1,E2,E1cb
In how many of these cases is entropy change positive?(Give reason for ur answer)
2.A catalyst decreases the energy of activation of the reaction A→B,del.H=37.012Kcal,by 2%.At 27°C 4*10^-8 %
of product molecules is able to cross over the potential barrier in absence of catalyst.How many times the catalyst will increase the reate of reaction at 27°C?
3.Two beakers one containing 20ml of a 0.05M aq. sol. of a non-volatile non-electrolyte and the other containing 20ml of a 0.03M NaCl sol. are placed side by side in a closed enclosure.What are the volumes of the two beakers when equlibrium is obtained?
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4 Answers
996(2) ln k = -Ea / (RT) + ln A where k is the rate constant, Ea is activation energy, R is the universal gas constant and A is some constant specific to a reaction
A more useful way to write this is in this case is:
k = Ae^ (-Ea / (RT) (Arrehenius equation)
k1k2 = (A.e^ (-Ea1 / (RT)) (A.e^ (-Ea2 / (RT))
The A cancels out.
Ea1 = (37012 - 2% of 37012)calorie
Ea2 = 37012 calorie
R=1.985 cal K-1 mol-1
T=300 K
u can calculate it .......
here we are getting the ratio of k1 and k2
u can also calculate k2and k1 individually as percentage of product molecules are given....
- Swarna Kamal Dhyawala By the what is the answer of this question?Upvote·0· Reply ·2013-07-18 23:42:53
- Swarna Kamal Dhyawala By the way what is the answer of this question?
- Anurag Ghosh A must be d collision frequency r8???.....a constant???
- Swarna Kamal Dhyawala hmmm
996volume of first beaker 17 ml
volume of second beaker 23 ml (approx)
- Swarna Kamal Dhyawala plzz say what is the answer of this question..
- Anurag Ghosh Well...I don't know the answer of any of these questions....:(
996E2 > E1cb > E1 >SN2 >SN1
elimination reaction have higher entropy than substitution becoz elimination occurs at higher temperature ( entropy increases when temperature increase) and second order kinetics have greater entropy than first order kinetics becoz more number of molecules are involved ....
- Anurag Ghosh More no. of molecules are involved or formed as products???
- Anurag Ghosh Aur E1cb ka E1 se zyada kyun hai entropy?
- Anurag Ghosh Arey haan...i didn't noticed...i asked how many of these will show +ve entropy change......Ab wat range u r taking for d entropy of these reactions???(Question becomes a bit confusing..:P).....This is an integer type question....
- Swarna Kamal Dhyawala well i guess it must be 3 (the elimination ones)
- Anurag Ghosh Why not the Substitution ones???.....
- Swarna Kamal Dhyawala becoz in elimination no. of products formed is more ........
and is carried out in high temperature also.......