Oill ••(•'''••• "AOM Huong dan gidi j^A
Dung dich mudi lam quy tim chuyen sang mau do khi dung dich mudi do c6 mdi trucmg axit => mudi tao tir axit manh va bazo yeụ
Do la cac mudi : Zn(N03)2, NH4CI, Al2(S04)3 ' *
Thi du: Khi hoa tan Zn(N03)2 vao H.O: ^ Zn(N03)2 > Zn-" + 2NO3
Z n- - H H 2 0 — Z n O H ^ . H ^ ,^ J
ZnOH* + H2O ^ l ! Zn(qH)2 + . i:r,>.^rh => dung djch c6 mdi tnrdng axit ( H ^ => lam quy tim hoa dọ Dap an dung la C.
Cty TNHH MTV DWH Khang Viet
2 Dung dich nao sau day c6 pH > 7?
A-D""g'^í^h Al2( S 0 4 ) 3 B. Dung djch CHjCOONa C. Dung djch NaQ D. Dung djch NH4ạ
Hu&ng dan gidi
Dung djch CH^COONa: CH^COONa -^CH^COO" + Na* CH3COO- + H2O ^ CH3COOH + OH~
=> Mdi tmomg kiem => pH > 7 Dap an dung la B. 3_ Trong cac dung djch: phenylamoni clorua, natri axetat, natri phenolat, natri
hidrosunfat, natri cloruạ NhQng dung djch c6 pH < 7 la
Ạ phenylamoni clorua, natri cloruạ I , 1 1 i +ff • ,
B. natri axetat, natri phenolat
C. phenylamoni clorua, natri axetat, natri phenolat, natri hidrosunfat.
D. phenylamoni clorua, natri hidrosunfat. S! «»f. ^
Hu&ng đn gidi
Dung djch c6 pH < 7 => dung djch (mudi) c6 mdi trudng axit. Do la cac dung djch. - Phenylamoni clorua Q H 5 N H 3 C I
- Natri hidrosunfat NaHS04. Dap an dung la D.
4. a c dung djch: NaHC03 (1), NaCl (2), NH4NO3 (3), CUSO4 (4), C H 3 C O O N H 4
(5), K o S O j (6). Cd gia tri pH nhir the naỏ Cho bie't K ^ = K
" • *^ N H + C H 3 C O O -
i«M fytniiim ,T " ;> j,(i>i •
A . ( l ) , ( 3 ) , ( 4 ) c 6 p H < 7 . B . ( 5 ) , ( 6 ) c 6 p H > 7 C. (2), (4), (5) cd pH = 7 D . ( l ) , ( 6 ) c d p H > 7 ^
Hu&ng đn gidi
X€i pH cac dung djch: m iJM 4- ,0:>
1) NaHCOj (axit yd'u - bazof manh): M T baza => pH > 7 2) NaCl (axit manh - baza manh): M T trung tính pH = 7 2) NaCl (axit manh - baza manh): M T trung tính pH = 7 3) NH4NO3 (axit manh - bazo ye'u): M T axit => pH < 7
4) CUSO4 (axit manh - baza ye'u): MT axit => pH < 7 , 5) C H 3 C O O N H 4 (axit yeu - baza yeu): M T trung tinh
( V i K , K _ ntn đ thiiy phSn ciia 2 ion nay la nhu nhau)
N H + C H 3 C O O • •' * •'
=>pH = 7 • •^'^ 6) K 2 S O 3 (axit yeu - baza manh): M T baza => pH > 7
=> (1); (6) cd pH > 7 * " Dap an dung la D.
Chu±: CH3COONH4 > C H 3 C O O " + N H ;
C C C
CH3COO" + H2O CH3COOH + O H '
( C - x ) X X