Intr-un pahar Berzelius cu 225g apa se adauga 25g CuSO4 5H2O. In alt pahar Erlenmeyer cu 50g solutie NaOH de concentratie 10% se adauga 2,3g sodiu . Calculati:a)concentratia procentuala a solutiei obtinute in paharul Berzelius b)concentratia procentuala a solutiei obtinute in paharul Erlenmeyer c)cantitatea de precipitat obtinuta la amestecarea solutiilor din cele doua pahare. Se dau:ZAr=18 , ZS=16 , ZNa=11 , ZK=19 , ZCl=17 , AK=39 , ACl=35,5 , ACu=64 , As=32 , AO=16 , AH=1 , ANa=23 , NA=6,0225 ·10²³
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2024-04-29 21:40:28
a) Masa molara CuSO₄*5H₂O=64+32+64+90=250g/mol 250g CuSO₄*5H₂O................................160gCuSO₄ 25g CuSO₄*5H₂O........................................x x=25*160/250=16g CuSO₄⇒9g H₂O masa de substanta=9+225+16=250g c=md*10/ms c=16*100/250 c=6.4% b) c₁=md₁*100/ms₁ md₁=c₁*ms₁/100 md₁=10*50/100 md₁=5g md final=5+2.3=7.3g ms final=50+2.3=52.3g c final=7.3*100/52.3 c final=13.95% c) CuSO₄+2NaOH=Cu(OH)₂+Na₂SO₄ precipitatul=Cu(OH)₂ Masa molara CuSO₄=160g/mol Masa molara Cu(OH)₂=64+2*16+2*1=98g/mol y=masa de Cu(OH)₂ obtinuta y=16*98/160=9.8g Cu(OH)₂
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