Question

Answer 1

Câu 1,2,3 cậu tự làm đc ko

Answer 2

a. PTHH:

Na₂CO₃ + 2HCl ---> 2NaCl + H₂O + CO₂ 

NaCl + HCl ---x--->

Ta có: \(n_{CO_2}=\dfrac{4,48:1000}{22,4}=0,0002\left(mol\right)\)

Theo PT: \(n_{HCl}=2.n_{CO_2}=2.0,0002=0,0004\left(mol\right)\)

Đổi 20ml = 0,02 lít 

=> \(C_{M_{HCl}}=\dfrac{0,0004}{0,02}=0,02M\)

b. Theo PT: \(n_{NaCl}=n_{HCl}=0,0004\left(mol\right)\)

=> \(m_{NaCl}=0,0004.58,5=0,0234\left(g\right)\)

c. Theo PT: \(n_{Na_2CO_3}=n_{CO_2}=0,0002\left(mol\right)\)

=> \(m_{Na_2CO_3}=0,0002.106=0,0212\left(g\right)\)

=> \(\%_{m_{Na_2CO_3}}=\dfrac{0,0212}{5}.100\%=0,424\%\)

\(\%_{m_{NaCl}}=100\%-0,424\%=99,576\%\)