Please HELP with parts B and C! THANK YOU! Express your answer using three signi
ID: 926453 • Letter: P
Question
Please HELP with parts B and C! THANK YOU!
Express your answer using three significant figures.
Consider the Daniell cell, for which the overall cell reaction is
Zn(s)+Cu2+(aq)Zn2+(aq)+Cu(s)
The concentrations of CuSO4 and ZnSO4 are 2.20×103m and 1.45×103m, respectively.
a. Calculate E setting the activities of the ionic species equal to their molalities.
E= 1.104V
b. Calculate ±,ZnSO4 for the half-cell solutions using the Debye-Huckel limiting law.
incorrect answers: 0.902, 0.6442, 0.44692
c. Calculate ±,CuSO4 for the half-cell solutions using the Debye-Huckel limiting law.
incorrect answers: 0.881, 0.7, 0.6998, 0.50691
d. Calculate E using the mean ionic activity coefficients determined in part (b) and part (c).
E = 1.103 V
Explanation / Answer
b). We can write 2.20×103m as 0.00220m also so,
I=M/2 (v+ z+2 v- z-2) =1/2(m+ z+2 m- z-2)
I= ½ (4 X 0.00220 mol kg + 42 X 0.00220 mol kg) = 0.220 mol kg
Ln ¥ =1.173 |z+ z-| sq root 1/mol kg -1.= -1.173x 4x sq root 0.220 =2.2005