De thi mon dien hoa de so 3

Cau 2: The nao la nguon dien hoa hoc? Nguon so cap, nguon thu cap? Tinh nang nguon

dien hoa hoc.

Tra loi:

Nguon dien hoa hoc la he thong co kha nag bien doi hoa nang thanh dien nang, hay noi

cach khac nguon dien hoa hoc la nguon dien ma dong dien duoc sinh ra tu nang luong

cua cac phan ung hoa hoc

Nguon so cap (pin) la nguon hoa hoc ma he thong sau khi phong dien thi cac chat hoat

dong sau khi phong dien da hoat dong da phan ung, kho tai sinh lai thanh chat hoat dong

ban dau nen thuong chi su dung 1 lan

Nguon dien thu cap (ac quy)la nguon hoa hoc co kha nang hoat dong lau dai nho tc thuan

ngich cua qua trinh phong nap. Khi nap dien thi no tich tru nang luong tu dong dien 1

chieu cua nguon ngoai nho 1 phan ung hoa hoc. Kh phong dien, nang luong do lai duoc

giai phong, toa ra thang dong dien mach ngoai do qua trinh nguoc cua phan ung tren.

Tinh nag cua nguon dien hoa hoc:

Suc dien dong : la gt tong dai so cua buoc ngay dien the tren cac dien cuc khi

mach ho: E= (phi)c – (phi)a

Dien the U= (V) la gia tri do dc khi nguon lam viec

U= E - Epc - IR

Dung luong C la luong dien ma nguon co the cung cap khi phong dien o nhung dk

nhat dinh

Acquy: + dung luong nap: luong dien cung cap de day binh

+ dung luong phong: luong dien phong ra

Su tu phong dien: la hien tuong mat mat C mot cach vo ich khi mach ngoai ho

Cau2: dac diem lop ma Ni? Dac diem cua qua trinh ma Ni? Trong dung dich ma Ni co

ban co nhung thanh phan nao? Tac dung va anh huuong cua tung thanh phan?

Tra loi:

Dac diem cua lop ma Ni: (dac diem cua kim loai Ni)

La KL co mau trang, anh vang

The dien cuc tieu chuan = -0.25V -> la lop ma catot doi voi nen kl den

Tren be mat kl Ni co lop mang oxit rat mong, kin xit, trong suot, rat ben

Lop ma Ni co nhieu lo ho

Lop ma Ni de danh bong

Thuong dung de ma lot Cu hoac ma nhieu lop.

Dac diem wua trinh ma Ni:

Mat do dong trao doi ion nho => chi so β lon => toc do tao mam lon, tinh the nho

Phan cuc catot rat lon ngay ca khi ket tua tu dung dich muoi don nen lop ma co

cau truc nho min

Qua the thoat H2 nho => H2 de thoat ra

Trong dung dich ma Ni co ban co nhung thanh phan sau:

NiSO4.7H2O : 150 – 400 g/l

NiCl2.6H2O : 20-80g/l hoac NaCl 10-40 g/l

Chat dem H3BO3: 10- 40 g/l (toi uu la 25 g/l)

Ngoai ra con co them NaSO4, MgSO4.7H2O, NaF, C12H25SO4Na)

Tac dung cac thanh phan:

NiSO4: la cau tu chinh cung cap ion Ni2+

NiCl2: la cau tu ching cung cap Cl- , lam giam phan cuc anot, giup anot de tan

(chong thu dong anot)

H3BO3: chat dem H25SO4Na): chat on chong cham kim, giam suc cang be mat

Cau 3: gia thich tai sao khi phan huy hon hong phai dung dien cuc than chi:

Hon hong sau khi ra khoi tb dien phan thi vao tb phan huy cho ra san pham cuoi

cung theo pt: HgnNa + H2O-> NaOH + H2 + nHg

Ban chat cua qua trinh phan huy hon hong la su hinh thanh mot pin dien, trong do

anot chua hon hong, con catot la Hg, tai do giai phong H2. so do pin dien:

(-)HgnNa│ NaOH + H2O │Hg(+)

Toc do giai phong hidro phu thuoc vao qua the thoat hidro cua thuy ngan, tuy nhien thuy

ngan co qua the thoat hidro lon, vi vay hidro thoat cham, nang suat kem, do do pai them

vat lieu co qua the thoat H2 nho VD: Ti, Pt, Gr…. Nhung cac kim loai ke tren hau het lai

tao hon hong voi thuy ngan, tru Gr, hon nua Gr lai re tien, de kiem nen trong cong nghiep

nguoi ta dung dem Gr de thuc day qua trrinh phan huy hon hong