- vdi phi kim manh Cdng thftc hoa hoc ciia :
LUYEN TAP V E: THANH PHAN CAU TAO NGUYEN TCT KHOI LUONG cCiA NGUYEN TQ OBITAN NGUYEN T Q
1.65. Cation R"^dugc tao thanh do nguyen tf tR mdt di 1 electro nd ldp vd
ngoai cung. Nhu vdy, nguyen tft R cd them 1 electron so vdi sd electron 2p^ cua R .
Theo quy tdc sdp xep electron vao cac d lugng tft thi d tiép sau 2p la d 3s. Nhu vdy, nguyen tft R cd cd cau hinh electron va phan bd electron theo obitan la :
m [TTITTTTTI Q ]
Is^ 2s^ 2p^ 3s^
1.66. + Nguyen tft cd Z = 9 vdi cáu hinh electron : Is^ 2s^ 2p^ cd 7 electron d
ldp ngoai cung. Nguyen td nay la phi kim.
+ Nguyen tft cd Z = 11 vdi cdu hinh electron : Is^ 2s^ 2p^ 3s^ cd 1 electron duy nhdt d ldp ngoai cung. Nguyen td nay la mgt kim loaị
+ Nguyen tft cd Z = 16 vdi cdu hinh electron : Is^ 2s^ 2p^ 3s^ 3p^ cd
6 electron d ldp ngoai ciing. Nguyen td nay la mdt phi kim.
+ Nguyen tft cd Z = 20 vdi cdu hinh electron : Is^ 2s^ 2p^ 3s^ 3p^ 4s^ cd 2 electron d ldp ngoai cung. Nguyen td nay la kim loaị
1.67*. Phdn tft M2X trung hoa dien dugc tao thanh do su kit hgp 2 nguyen tft
M vál nguyen tft X.
Ggi sd proton trong hat nhdn va sd electron cia nguyen tft M la Pj va Zj, sd proton trong hat nhdn va sd electron ciia nguyen tft X la P2 va Z2. Cac nguyen tft trung hoa dien nen ta cd P] = Z, ; P2 = Z2. Ni va N2 tuong ftng la sd natron trong hat nhdn cua cac nguyen tft M va X. Sd proton, electron va natron khdng bi thay đi khi xay ra phan ftng hoa hgc kit hgp hai nguyen tft M vdi 1 nguyen tft X. Sft dung cac dilu kien đu bai ra ta cd he cac phuong trinh bdc 1 sau :
+ Trong phdn tft MjX cd tdng sd hat (p, n, e) la 140 hat:
2(2Pi+Ni) + 2P2 + N2 =140 (1) + Trong phdn tft M2X sd hat mang dien nhilu hon sd hat khdng mang dien la 44 hat:
4Pi + 2P2 - Ni - N2 = 44 (2) + Sd khd'i cua nguyen tft M ldn hon sd khdi cua nguyen tft X la 23 :
+ Tdng sd hat (p, n, e) trong nguydn tft M nhilu han trong nguydn tft X la 34 hat:
2Pi + Ni = 2P2 + N2 + 34 Giai he phuofng trinh 4 dn sd, thu dugc : Nguyen td M cd Zi = Pi = 19
Nguyen td X cd Z2 = P2 = 8
Cdu hinh electron nguyen tft cfta cac nguyen td nhu sau + Nguyen tft M la kali vdi cd'u hinh electron :
(4)
11 11 mill 11 1111 1
Is^ 2s^ 2p^ 3s' + Nguyen tft X la oxi vdi cdu hinh electron :
3P^ m 4s' 11 I I Is^ 2s^ 2p" Cdng thftc phdn tft cua MjX la K2Ọ
1.68*. a) Ggi Pj, P2 la sd proton cd trong nguyen tft M va X tuang ftng bdng sd electron cfta hai nguyen tft naỵ Ni vd N2 tuang ftng la sd natron trong hat nhdn cua cac nguyen tft M va X. Sft dung cac dilu kien đu bai ra ta ed he cac phuang trinh bdc 1 sau :
+ Trong phdn tft MX2 cd M chidm 46,67% vl khd'i lugng :
+ Trong hat nhdn M sd natron ldn han sd proton 4 hat
Ni = Pi + 4 (2) + Trong hat nhdn X cd N2 = P2 (3) + Trong phdn tft MX2 cd tdng sd proton bdng 58 :
Pi + 2P2 = 58 (4) Giai he phuang trinh 4 dn sd, thu dugc Pi = 26, Ni = 30
P2 = N2 = 16
Ta cd : Â = 26 + 30 = 56 (M la Fe) Ax = 16 + 16 = 32 (X la S). b) Cdng thftc phdn tft cua A la FeS2 (pirit sdt).
Chuang2