Question

[aiamni]

giúp mk vs ạ 😢

Answer 1

[hnamyuh]

Câu 1 : 

Gọi $m_{dd} = a(gam)$
$n_{NaOH} = \dfrac{a.20\%}{40} = 0,005a(mol)$
$n_{Ba(OH)_2} = \dfrac{a.8,55\%}{171} = 0,0005a(mol)$

$n_{HNO_3} = \dfrac{224}{1,1.1000}.4,5 = 0,9(mol)$

$NaOH + HNO_3 \to NaNO_3 + H_2O$
$Ba(OH)_2 + 2HNO_3 \to Ba(NO_3)_2 + 2H_2O$
Theo PTHH : 

$0,005a + 0,0005a.2 = 0,9 \Rightarrow a = 150(gam)$

Answer 2

[hnamyuh]

Câu 2 : 

Gọi thể tích dung dịch cần tìm là V(lít)

$n_{H_2SO_4} = 1,1V(mol) ; n_{HCl} = 1,98V(mol)$

$\Rightarrow n_H = 1,1V.2 + 1,98V = 4,18V(mol)$
$n_{NaOH} = 0,19.3 = 0,57(mol) ; n_{Ba(OH)_2} = 0,19.4 = 0,76(mol)$
$\Rightarrow n_{OH} = 0,57 + 0,76.2 = 2,09(mol)$
$H + OH \to H_2O$
$\Rightarrow 4,18V = 2,09 \Rightarrow V = 0,5(lít)$