C. b anot xayra sir oxi hoa: Cu > C u^^+2e
6.Dien phan 200ml dung dich chiia dong thai AgNO, IM va Cu(NO,): 2M trong thofi gian 48 phiit 15 giay, vdi cuang do dong dien 10 ampe (dien cue tro, hieu
thofi gian 48 phiit 15 giay, vdi cuang do dong dien 10 ampe (dien cue tro, hieu suat dien phan la 100%). Siiu dicn phan de yen binh dicn phan cho ciic phan u n g xay ra hoan toan thu duoc V lít khi N O (san phdm khu duy nhat, dktc). Gia trj cua V la
Ạ 3,36 B.6,72 C. 1,68
Huong đn gidi
Theobai ra: nAj.No, =0.2mol;ncu(NO3)2 =0.4mol
D. 1,12.
PTDP: 2 A g N O ,+ H 2 0- > 2 A g + 2HN03 + ^ 0 2
0,2 . 0 , 2 - > 0 , 2
l i i i C ' " ; 1 • •
Cu(N03)2 + H 2 O ^ C u + 2 H N 0 3+ - 0 2 X - > X ^ 2x „ , I . t 10.(48.60+15) Taco: — = =0,3 F 96500 => 0,2. 1 + X. 2 = 0,3 => X = 0,05 (mol) Suy ra: Sau khi ngimg dien phan c6:
0,2mol A g ; 0,05mol Cu; 0,2 + 0,1 =0,3 mol HNO3
3Cu + 8 H N O 3 3Cu(NO3 )2 + 2NO t + 4 H 2 O
0,05 ^ 0 , 4 / 3 ^ 0,1/3 3 A g + 4 H N 0 3 - ^ 3 A g N 0 3 + N 0 T + 2H2O •>if.i .•• A PTPi;: 0,5 V 3- M I 3 ) 0 5 12 v a y V = V ^ o = 0,1 0,5 • + .22,4 = 1,68 (lit) D a p a n diing l a C. y J \ j
7. Tien hanh dien phan 200 ml dung djch X g6m HCl 0,6M va CUSO4 I M \6\
cuomg do dong dien I = 2,68 ampe trong thdi gian 2 gior (dien cue tro, c6 mang
ngan, hieu suát dien phan 100%). The tích khi thoat ra b anot ( 0 dktc) la Ạ 1,792 lit B. 2,688 lit C. 2,24 1ft D . 1,344 lit
Hu&ng dan gidi
Theo bai ra: nHci = 0,12 mol; n^^^^ = 0,2mol ,/ ()
6 anot (cue duong):
Trudc tien: cr - e -cu t
2 ^ (1)
0,12 - Sau d o (CO thé c6): 2H2O - 4e
0,06 (mol) 4H* + O , T (2) • n .n.F
Thdi gian đ oxi hod het ion CP: t, = 0,12.1.96500 I 2,68 =4320(giay) = l,2(gic0 Vi t, = 1,2 (gior) < 2(gi6r) => c6 (2) xay rạ
Thdi gian oxi hoa H^O (xay ra qua trinh (2)) t, = 2 - 1,2 = 0,8 (gior) = 2880 (giSy)
' 2 68 9880
Ap dung c6ng thurc Faraday cho (2): n^^ = ' " ° ; ^ ^ ^ = 0,02(mol)
4.96500
V a y t6ng the tích khi thoat ra a anot:
w Va„„, - Vc,2 + =(0,06+0,02).22,4
= 1,792 (lit). D a p a n diing l a A .