Răspuns:
1.
MH2S=2×1+32=34g/mol
n=m/M=34/34=1mol
2.
MCO=12+16=28g/mol
28gCO..........12gC.................16gO
100gCO...........xgC....................ygO
x=100×12/28=calculeaza
y=100×16/28=calculeaza
3.
MCO=12+16=28g/mol
m=n×M=2×28=calculeaza
4.
C+O2→Co2
2Al+3Cl2→2AlCL3
Cl2+H2→2HCl
2Na+Cl2→2NaCl
Explicație: