mbacl2=\(\dfrac{C\%.m_{dd}}{100\%}=\dfrac{5,2.200}{100}=10,4\left(g\right)\)
mh2so4=\(\dfrac{C\%.m_{dd}}{100\%}=\dfrac{20.58,8}{100}=11,76\left(g\right)\)
nbacl2=\(\dfrac{m}{M}=\dfrac{10,4}{208}=0,05\left(mol\right)\)
nh2so4=\(\dfrac{11,76}{98}=0,12\left(mol\right)\)
a, pthh: BaCl2 + H2SO4 \(\rightarrow\) BaSO4 + 2HCl
\(\Rightarrow\)H2SO4 dư
\(\Rightarrow\) nBaso4=nbacl2=nhcl=0,05(mol)
\(\Rightarrow\)mBaso4=n.M=0,05.233=11,65(g)
b, mdd HCl=(mdd bacl2 + mdd h2so4)-mbaso4=(200+58,8)-11,65=247,15(g)
mHCl=n.M=0,05.36,5=1,825(g)
\(\Rightarrow\) C%HCl=\(\dfrac{m_{ct}}{m_{dd}}.100\%=\dfrac{1,825}{247,15}.100\%=0,74\%\)
quên mik chưa tính C% của chất dư tham gia pứ
b, nh2so4 dư=nBacl2=0,05(mol)
mh2so4 dư=n.M=0,05.98=4,9(g)
\(\Rightarrow\) C%h2so4 dư=\(\dfrac{4,9}{58,8}.100\%=8,33\%\)