MQT PHAN TU CHAT A C6 D�G RX2 (R, X LA CAC DON NGUYEN TU), TRONG D6...

2) MQt phan tu chAt A c6 d�g RX

2

(R, X la cac don nguyen tu), trong d6 R chi�m 46,67 %

v� kh6i lu()'11g. T6ng s6 h�t proton, ncrtron, electron trong m<)t phan tu chAt A la 178. Trong nguyen

tir R, s6 h?t mang di�n nhi�u hon sf> h�t kh6ng mang di�n la 22. Trong nguyen tir X, s6 h�t mang

di�n nhi@u gAp d6i s6 h�t kh6ng mang di�n.

a) Xac djnh R va X.

b) 06t chay hoan toan m gam chfit A trong oxi vira du, toan b9 san phAm khi thu dugc hfip

tlw h@t b&i I lit dung dich chua h6n hQ'P g6m Ba(OH)

i

0,2M va KOH 0,2M, sau phan irng thu duqc

dung djch Y va 32,55 gam kSt tua. Xac dinh gia tri cua m.

Cau II. (2,0 iliim): --�

..

I) C6 4 19 h6a chfit mftt nhan dliQ'c ki hi�u la A, B, C, D. M6i 19 dvng m(>t trong cac dung

djch chftt: HCl, NaHS0

4,

BaC1

2,

NaHS0

3•

0S xac djnh h6a chfit trong m6i 19, nguai ta ti�n hanh

cac thi nghi�m va thfty hi�n tuQ'ng nhu sau:

-Cho dung djch A tac d\mg v6i dung djch B thfiy xuftt hi�n kSt tua.

-Cho dung djch B hay D tac d\lllg vm dung dich C d�u thfty c6 b9t khi khong mau, mui h�c bay ra.

-Cho dung djch D tac dgng v6i dung djch A thi khong thfry hi�n tuQTig gi.

Xac dµm h6a chfit d\l'Ilg trong cac 19 A, B, C, D va vi@t phuang trinh cua cac phan ung xay ra.