W(в-ва)=m(в-ва)/m(р-ра)*100%
m(H2SO4)=200г
m(р-ра)=2.7+200=202.7г
w(H2SO4)=200/202.7=0.986=98.6%
BaSO3->SO2->H2SO3->Na2SO3->SO2->
1)BaSO3=BaO+SO2↑
2)SO2↑+H2O=H2SO3
3)H2SO3+2 NaCl=Na2SO3+2 HCl
4)Na2SO3=Na2O+SO2↑
2BaSO3+4HCl=2BaCl2+2H2O+SO4
2Ba+2SO3+4H+4Cl=2Ba+4Cl+2H2O+SO4
4H+2SO3=2H2O+SO4
<span>BaCl</span><span>2</span><span> + 2AgNO</span><span>3</span><span> => Ba(NO</span><span>3</span><span>)</span><span>2</span><span> +2AgNO</span><span>3</span>