- Hoatan het phd n2 bang dung dich HNO3 dac, nong (du) tháy c6 11,76 lit khi bay ra (dktc).
6. Chi dung them quy tim, bang phuong phap hoa hoc c6 the phan biet duoc cac dung djch rieng bi6t trong day nao sau daỷ
dung djch rieng bi6t trong day nao sau daỷ
Ạ A I C I 3 , NaNOj, NaOH, B a d , B. CaCU, Na3C03, NH4CI, NaOH C. NaCl, BăN03)2, NaOH, HCl D. NaOH, NaN03, Na:S04, NH4CI
Hu&ng đn gidi
Chi dung quy tim c6 thé nhan biet duoc cac dung djch trong day: Cad,, Na2C03,
NH4CI, NaOH.
+ NH4CI (đ): Lam quy tim hoa dọ NH4C1->NH;+Cr
N H ^ ^ N H j + H ^ • CaCl2(đ). khong d6i mau quy tim (cac ion Cá*, C I ' la ion trung tinh). .
NaOH; Na2C03: lam quy tim hoa xanh.
N a O H - > N a * + O H " - / i , v H i
Na2C03->2Na*+CO|- C O f - + H 2 0 ^ H C 0 3 + O H -
Cho CaCK vao 2 mSu lam quy tim hoa xanh (NaOH, NâCOj): * M5u cho ket tua => NâCOj.
Na2C03 + CaCl2 ->CaCOj i + 2NaCl
* M5u con lai la NaOH Dap an diing la B.
Phdn loqi vd phUcmgphdp gidi nhanh BT Hoa hoc 12 - CuThanh Todn
C. Khong phan bifit NaQ va BaCNOj), D. Kh6ng phan bidt NaNO, va Na2S04.
7. Dé tach AUOj ra khoi h6n hop g6m CuCOH),, AUOj ma kh6ng lam thay d6i kh6'i luong cua no, ngucri ta chi cdn dung
Ạ dung dich NaOH. B. dung dich H Q .
C. dung djch NH3. , D. dung dich NaOH vk đ H Q .
Hu&ng dan gidi
De tach AW, ra khoi h6n hop v6i Cu(OH)2, chi cdn dung dung dich NHji Cu(OH)2 + 4NH3 - > [ C u{ N H 3) ^ ] ( O H) 2 (Tan)
AI2O3 + NH3 (đ)-> Kh6ng xay rạ
Dap an dung la C. 8. Co 3 goi b6t trang kh6ng ghi nhan: (1) NaCl va KCl; (2) NạCOj va K.COj, (3)
MgS04 va BaQ,. Khi chi dung them 1 chat nao trong s6' cac chat sau day thi
khong phan biet duoc 3 goi b6t trang tren bang phuong phap hoa hoc? Ạ dung dich HCl B. H^O
C. dung dich BaCOH). D. dung dich H2SO4
Hu&ng dan gidi
Khi sir dung m6t trong cac thu6'c thir la dung djch HCl, HjO hoac dung dich
H2SO4 deu CO th^ phan biet duoc 3 goi b6t trang tren. - Chi dung dung djch BaCOH),:
Bâ* + SÔ" > BaS04 i (trang) :
Bâ* + C 0 ^ - >BaC03 i (trang)
Kh6ng thé phan biet duoc 2 két tija trSng nay nen khdng phan biet duoc hai goi b6t tan đa la (NâCOj va K.COj) va (MgS04 va BaQ,)
Dap an dung la C.
ChU v.- Khi hoa tan h6n hop b6t MgS04 va BaCU vao nude hoac dung djch cac
chat thi xay ra phan dug trao d6i ion trong dung djch tao ra két tiia trang: BaClj +MgS04 >BaS04 i + MgCl2