Electrochemistry

 

 80) (a) I = 5.25 A

            Δt = 2.50 days x 24 hr/1 day x 3600 s/1 hr = 2.16 x 105 s

 

            Mg2+(l) + 2e- Mg(s)

 

            mMg = 5.25 C/s x 2.16 x 105 s x 1 mol e-/96500 C x 1 mol Mg/2 mol e- x 24.30 g Mg/1 mol Mg

            mMg = 143 g Mg

 

       (b) mMg = 10.00 g Mg          I = 3.50 A

 

            Q = I/Δt

            Δt = Q/I

            Δt = (10.00 g Mg x 1 mol Mg/24.30 g Mg x 2 mol e-/1 mol Mg x 96500 C/1 mol e-)/(3.50 C/s x 60 s/min)

            Δt = 378 min