a) mCuO= 3,2/80= 0,04(mol)
mH2SO4= 40%.100=40(g)
=>nH2SO4=40/98=20/49(mol)
PTHH: CuO + H2SO4 -> CuSO4 + H2O
Ta có: 0,04/1 < 20/49:1
=> H2SO4 dư, CuO hết -> Tính theo nCuO
=> nH2SO4(P.Ứ)=nCuSO4=nCuO=0,04(mol)
=>mH2SO4(p.ứ)=0,04.98=3,92(g)
b) mCuSO4=0,04.160=6,4(g)
c) mH2SO4(dư)= 40 - 3,92= 36,08(g)
mddsau= 3,2+100=103,2(g)
=>C%ddH2SO4(dư sau p.ứ)= (36,08/103,2).100=34,961%