Question

Salut! Va rog sama ajutati cu aceasta problema de chimie. (rezolvare)
Din ce cantitate de acid clorhidric 37% se poate extrage clorul necesar obtinerii a 40gg FeCl2 5%.

Answer 1

$Fe+2HCl=FeCl_2+H_2$

$Masa \ de \ FeCl_2 \ pur \ din \ solutie \ este \ m_{FeCl_2}=\frac{5*40}{100}=2g$

$M_{FeCl_2}=M_{Fe}+2M_{Cl}=56g+2*35g=126g$

$126g \ FeCl_2..........70g \ Cl$

$2g \ FeCl_2..........x \ g \ Cl$

$\frac{126}{2}=\frac{70}{x}$

$x=\frac{2*70}{126}=\frac{140}{126}=1,11g$

$M_{HCl}=M_{H}+M_{Cl}=1g+35g=36g$

$36g \ HCl..........35g \ Cl$

$x \ g \ HCl..........1,11g \ Cl$

$\frac{36}{x}=\frac{35}{1,11}$

$x=\frac{36*1,11}{35}=1,14g$

$Cantitatea \ de \ 1,14g \ HCl \ reprezinta \ cantitatea \ de \ substanta \ pura \ ce \ se \ gaseste \ in \ solutia \ de \ concentratie \ de \ 37\%$

$c=\frac{m_d*100}{m_s}=\textgreater m_s=\frac{m_d*100}{37}=\frac{1,14*100}{37}=3,08g$

$Raspuns:3,08g$