- Hoatan het phd n2 bang dung dich HNO3 dac, nong (du) tháy c6 11,76 lit khi bay ra (dktc).
9. C o4 mSu b6t kim loai Na, Al, Ca, Fẹ Chi dung nuoc lam thu6c thir thi s6' kim loai CO the phan biet duoc t6'i da la bao nhieủ
loai CO the phan biet duoc t6'i da la bao nhieủ
A . l B.2 C.3 D . 4
Hu&ng đn gidi
Chi dung nude c6 thé nhan biet duoc 4 kim loaị Cho cic kim loai v^o nuoc: - Phan ling manh, c6 khi thoat ra nhanh, dung dich trong su6't => kim loai Na - Phan umg manh, c6 khi thoat ra nhanh, dung dich trang due => Kim loai Ca
- Dung dung dich NaOH cho tac dung vdfi 2 kim loai c6n laị + Kim loai bj tan, c6 khi => Kim loai A l .
+ Kim loai kh6ng phan tag => Kim loai Fẹ
PTHH: 2 N a + 2 H 2 O > 2 N a O H + H2 t * ' ' - J*^
Ca + 2H2O > CăOH)2 i + H2 t
l20 > 2NaA102 /2
2A1 + 2NaOH + 2 H , 0 > 2NaA10, + 3 H , t ' '
Dap an dung la D.
10. Chi dung them m6t hoa chat, hay phan biet cac chát trong nhihig day sau va viét phuong trinh hoa hoc d^ giai thich.
a) Cac kim loai: A l , Mg, Ca, Na b) Cac dung dich: NaCl, CaCU, AICI3
c) Cac chat b6t: CaO, MgO, AhO,
Hu&ng đn gidi , i '
Nhan biét cac chát:
a) Dung them hoa chát la HjO: - Cho H2O vao cac kim loai
+ Kim loai tan nhanh, khi thoat ra manh, dung dich trong su6't => Kim loai Nạ 2Na + 2H2O > 2NaOH + H j t
+ Kim loai tan nhanh, c6 khi, dung djch trang due => Kim loai Ca
Ca + 2H2O > CăOH)2 4- + H2 T iOJ
trang + Hai kim loai kh.6ng tan la A l , Mg.
- Cho dung djch NaOH vao 2 kim loai con lai: + Kim loai tan, c6 khi => kim loai Al
2AI + 2NaOH + 2H2O > 2NaA102 + 3H2 t
+ Kim loai kh6ng tan la M g ' b) - Dung them NâCOj.
Cho NâCO, vao cac dung djch:
+ Dung djch c6 két tiia trang xuát hien => CaQ, Na2C03 + CaClj > CaCOj i + 2NaCl
trang
+ Dung djch c6 khi thoat ra, c6 két tiia trang AICI3.
3Na2C03 + 2Aia3 + 3H2O > 2Al(OH)3 4- + SCOj t+ 6 N a a
+ Dung dich con lai la NaCl. c) - Dung them nudẹ
- Cho H.O vao cac b6t:
+ Bot bi tan => CaO , tt ;
CaƠ H 2 O > CăOH)2
+ Khong tan => MgO, AUO,
- Cho dung djch CaCOH). vao 2 bot con lai: + B6t bi tan => AUO,
AI2O3 + CăOH)2 > C a(A102)2 + H j O
+ Bot kh6ng tan => MgỌ