Learn to Create a Robotic Device Using Arduino in the Free Webinar. Register Now
One of our academic counsellors will contact you within 1 working day.
Click to Chat
1800-1023-196
+91-120-4616500
CART 0
Use Coupon: CART20 and get 20% off on all online Study Material
Welcome User
OR
LOGIN
Complete Your Registration (Step 2 of 2 )
Free webinar on Robotics (Block Chain) Learn to create a Robotic Device Using Arduino
30th Jan @ 5:00PM for Grade 1 to 10
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?
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
Post Question
Dear , Preparing for entrance exams? Register yourself for the free demo class from askiitians.
points won -