Question

mọi người giúp mình câu 3, câu 4 với ạ

 

Answer 1

\(m_{BaCl_2}=\dfrac{20,8.20\%}{100\%}=4,16\left(g\right)\)

=> \(n_{BaCl_2}=\dfrac{4,16}{208}=0,02\left(mol\right)\)

\(m_{H_2SO_4}=\dfrac{39,2.10\%}{100\%}=3,92\left(g\right)\)

\(\Rightarrow n_{H_2SO_4}=\dfrac{3,92}{98}=0,04\left(mol\right)\)

\(BaCl_2+H_2SO_4\rightarrow BaSO_4+2HCl\)

0,02          0,02          0,02          0,04

LTL: \(\dfrac{0,02}{1}< \dfrac{0,04}{1}\) => H₂SO₄ dư, BaCl₂  đủ

\(m_{H_2SO_{4\left(dư\right)}}=\left(0,04-0,02\right).98=1,96\left(g\right)\)

\(m_{BaSO_4}=0,02.233=4,66\left(g\right)\)

\(C\%_{ddH_2SO_4}=\dfrac{1,96.100}{20,8+39,2}=3,27\%\)

\(C\%_{ddHCl}=\dfrac{0,04.36,5.100}{20,8+39,2}=2,43\%\)

Answer 2

???

Answer 3

Chữa gì mà chằng chịt vậy má