I.
A -adevarat
B.F
C. A
D.A
II.
50 g H2SO4 20%=> 10 g H2SO4 pur=> m H2O= 40 g
40 g H2SO4 18%=> 7.2 g H2SO4 pur=> m H2O=32.8 g
30 g H2SO4 16%=> 4.8 g H2SO4 pur=> m H2O= 25.2 g
m H2SO4 total= 22g
m H2O total= 98 g
ms total= 120g => c= 22/120 x100= 18.33%
III.
a) [tex]Cu Cl_{2} + 2AgN O_{3} =\ \textgreater \ 2AgCl + Cu( NO_{3}) _{2}
[/tex]
[tex]Cu ^{2+} +[tex]2Ag^{1+} + 2 Cl^{1-} =\ \textgreater \ 2AgCl(s)[/tex] + 2Ag^{1+} +( NO_{3} ) ^{1-} =\ \textgreater \ 2AgCl(s) + Cu ^{2+} + 2(NO _{3} )^{1-}[/tex]
b) [tex] BaCl_{2} + H_{2}SO_{4} =\ \textgreater \ BaSO_{4} + 2 HCl[/tex]
[tex]Ba^{2+} + 2Cl^{1-} + 2H^+ + SO_4^{2+} =\ \textgreater \ BaSO_4(s) + 2H^+ + 2Cl^-[/tex]
[tex]Ba^{2+} + SO_4^{2-} =\ \textgreater \ BaSO4 (s)[/tex]
c)K[tex]K_2CO_3 + 2HCl =\ \textgreater \ 2KCl + CO_2 +H_2O[/tex][tex]2K^+ + CO_3^{2-} + 2H^+ +2Cl^- =\ \textgreater \ 2K^+ + 2Cl^- + CO_2 + H^+ + HO^-[/tex]
2[tex]2K^+ +CO_3^{2-} + 2Cl^- =\ \textgreater \ 2KCl + CO_2[/tex]
4) b
5)[tex]CuO + H_2SO_4 =\ \textgreater \ CuSO_4 + H_2O[/tex]
v ac. sulfuric = 200 mL=0.2 L
C=0.3M
n= 0.3 x 0.2 = 0.06 mol [tex]H_2SO_4[/tex]
1 mol ac sulfuric .... 1 mol piatra vanata
0.06 mol ac sulfuric...0.06 mol piatra vanata
m cristalohidrat = 0.06 mol x 249.685 g/mol = 14.98 g [tex]CuSO_4[/tex]×[tex]5H_2O[/tex]
