Question

Cantitatea de HCl dizolvat in 36.5 grame solutie ce contine 0.3% HCl este:
a) 0.3 moli
b)1.095 g
c)0.003 moli
d)0,01095 g

Answer 1

Răspuns:

c)0,003moli

Explicație:

$w=\frac{m(sub)}{m(sol)} *100%$

$m(sub)=\frac{w*m(sub)}{100}$

$m(sub)=\frac{36.5g*0.3}{100} =0.1095g$

$M(HCl)=36.5g/mol$

$n=\frac{m(sub)}{M(HCl)}$

$n=\frac{0.1095g}{36.5g/mol} =0.003$mol