Đáp án:
$a,m_{Fe}=15,4\,(g)$
$b,C\%=16,2\%$
Giải thích các bước giải:
$Fe+2HCl\rightarrow FeCl_2+H_2$
$a,m_{HCl}=\dfrac{200.10}{100}=20\,(g)$
$⇒n_{HCl}=\dfrac{20}{36,5}=\dfrac{40}{73}\,(mol)$
$⇒n_{Fe}=\dfrac{1}{2}.n_{HCl}=\dfrac{20}{73}\,(mol)$
$⇒m_{Fe}=\dfrac{20}{73}.56=\dfrac{1120}{73}=15,4\,(g)$
$b,n_{H_2}=n_{Fe}=\dfrac{20}{73}\,(mol)$
$⇒m_{H_2}=\dfrac{20}{73}.2=\dfrac{40}{73}\,(g)$
$⇒m_{dd}=\dfrac{1120}{73}+200-\dfrac{40}{73}=\dfrac{15680}{73}=214,8\,(g)$
$n_{FeCl_2}=n_{Fe}=\dfrac{20}{73}\,(mol)$
$⇒m_{FeCl_2}=\dfrac{20}{73}.127=\dfrac{2540}{73}=34,8\,(g)$
$⇒C\%=\dfrac{34,8.100\%}{214,8}=16,2\%$.