I.
A = 85 Z = 37
=> 37p+ , 37e-
din A = Z+n0 => n0 = A-Z
= 85-37 = 45
(1)K-2e- (2)L-8e- (3)M-8e- (4)N-18e- (5)O-1e-
perioda 5
grupa I-A
valenta 1
II.
A.
1. Cu(NO3)2 = sare
2. CaO = oxid metalic (bazic)
3. ZnSO4 = sare
4. Na2S = sare
5. H2CO3 = acid
6. Fe(OH)3 = baza
7. Al2(HPO3)3 = sare acida
8. HNO3 = acid
9. BaCO3 = sare
10. NH4Cl = sare
B
NO = moxid de azot, oxid acid
CuO = oxid de cupru (II) , oxid bazic
HNO3 = ........ vezi mai sus
FeSO4 = sulfat fier (II), sare
MgCO3 = carbonat de Mg, sare
LiBr = bromura de litiu, sare
P2O5 = pentaoxid de difosfor, oxid nemetalic
Fe2O3 = oxid de fier (III) , oxid metalic
Zn(OH)2 = hidroxid de zinc, baza
HF = acid fluorhidric, hidracid
Ca(H2PO3)2 = fosfit diacid de calciu , sare acida
III.
A.
NaOH = hidroxid de sodiu
M = 23+16+1 = 40 g/mol
1 mol NaOH ........... 40g ............ 1g H
360000g ......... x = 9 kg H
B.
H2SO4 = acid sulfuric
M = 2x1+32+16x4 = 98 g/mol
1 mol .......... 98g ........... 48g O
490g .......... x = 240g O
Ca(OH)2 = hidroxid de calciu (var stins)
M = 40+(16+1)2 = 74 g/mol
1 mol .............. 74g ................. 32g O
n g .................. 240g O
= 555g Ca(OH)2
IV.
notam clorura unui metal trivalent MCl3
M = Am+3x35,5 = Am+106,5 g/mol
100% ................................... 67,19% Cl
Am+106,5 .......................... 106,5g Cl
=> Am = 52 => M = Cr
=> CrCl2
