×

#### Thank you for registering.

One of our academic counsellors will contact you within 1 working day.

Click to Chat

1800-1023-196

+91-120-4616500

CART 0

• 0

MY CART (5)

Use Coupon: CART20 and get 20% off on all online Study Material

ITEM
DETAILS
MRP
DISCOUNT
FINAL PRICE
Total Price: Rs.

There are no items in this cart.
Continue Shopping
```
Two weak acid solutions HA1 and HA2 each with the same concentration and having pka values 3 and 5 are placed in contact with hydrogen electrode (1 atm, 25 degree Celsius) and are interconnected through a salt bridge. The emf of the cell is?
Two weak acid solutions HA1 and HA2 each with the same concentration and having pka values 3 and 5 are placed in contact with hydrogen electrode (1 atm, 25 degree Celsius) and are interconnected through a salt bridge. The emf of the cell is?

```
6 years ago

Naveen Kumar
60 Points
```							The two half cells would have different value of H+ ion..........HA1....<.................>H+.+A1-HA2......<.........................>H+.+A2-H+(for HA1)=(Ka1*C)1/2..MH+(for HA2)=(Ka2*C)1/2..MH+...+e-.....>1/2H2writing for the half cell, EH+/H2=E0H+/H2-(0.0591/1)*log(pH2/[H+])writing these two half cell reaction for both the solution and taking the value of standard reduction potential of H=0E1H+/H2=0-(0.0591/1)*log(pH2/[H+]1)..[H+]=(Ka1*C)1/2…................(i)E2H+/H2=0-(0.0591/1)*log(pH2/[H+]2)..where..[H+]=(Ka2*C)½..........(ii)As pka1=3.so Ka=10-3and pka2=5.so ka2=10-5and so [H+] in HA1>[H+] in HA2 but the Ph2 =1atm in both the cases.So to make the overall reaction feasible Ecell>0 and so to get this positive value, we should make solution of HA1 as cathode and so Ecell can be given as Ecell=Ecathode-Eanode=E1-E2>0writing the cell notation:H2(1atm)/H+(in HA2)//H+(in HA1)/H2(1atm)So subtracting (ii) from (i),we have Ecell=E1H+/H2-E2H+/H2=-(0.0591/1)*log(pH2/[H+]1)..+...(0.0591/1)*log(pH2/[H+]2)=0.0591[log{[H+]1/[H+]2]=0.0591*log{Ka1C/Ka2C}1/2=0.0591*(1/2)*logKa1/Ka2=0.0591V
```
6 years ago
Think You Can Provide A Better Answer ?

## Other Related Questions on Physical Chemistry

View all Questions »

### Course Features

• 731 Video Lectures
• Revision Notes
• Previous Year Papers
• Mind Map
• Study Planner
• NCERT Solutions
• Discussion Forum
• Test paper with Video Solution

### Course Features

• 141 Video Lectures
• Revision Notes
• Test paper with Video Solution
• Mind Map
• Study Planner
• NCERT Solutions
• Discussion Forum
• Previous Year Exam Questions