Question

4 Determină numărul de moli de substanţă din:

a 5,6 g de oxid de calciu:
b 392 g de sulfat de cupru (II):
c 9,033 1020 molecule de acid sulfhidric:​

Answer 1

Răspuns:

n=m/M

sau

n=N/NA

1.m=5,6g CaO

MCaO=ACa+AO=40+16=56g/mol

n=5,6g/56g/mol=0,1 mol CaO

2.m=392 CuSO4

MCuSO4=ACu+AS+4AO=160g/mol

n=392g/160g/mol=2,45 mol CuSO4

3. N=9,033•10²⁰ molecule H2S

n=9,033•10²⁰molecule/6,022•10²³molecule/mol=0,0015 mol H2S