Question

Cho CaO vào 50g dd $C{H}_3$COOH 5% sau phản ứng thu được dd muối A

a) Tính m của muối A

b) Tính C% dd muối A

Answer 1

a)

$n_{CH_3COOH} = \dfrac{50.5\%}{60} = \dfrac{1}{24}(mol)$
$CaO + 2CH_3COOH \to (CH_3COO)_2Ca + H_2O$

Theo PTHH : 

$n_{(CH_3COO)_2Ca} = \dfrac{1}{2}n_{CH_3COOH} = \dfrac{1}{48}(mol)$
$\Rightarrow m_{muối} = \dfrac{1}{48}.158 = 3,292(gam)$

b) $n_{CaO} = \dfrac{1}{2}n_{CH_3COOH} = \dfrac{1}{48}(mol)$
$m_{dd\ sau\ pư} = m_{CaO} + m_{dd\ CH_3COOH} = \dfrac{1}{48}.56 + 50 = \dfrac{307}{6}(gam)$
$C\%_{(CH_3COO)_2Ca} = \dfrac{3,292}{\dfrac{307}{6}}.100\% = 6,43\%$