nH2= 2,24/22,4=0,1 mol

_{Ca + 2H2O =× Ca(OH)2 + H2}

_{0,1×= 0,1 0,1}

CaO+ H2O=× Ca(OH)2

mCa = 0,1 ×40=4 gam

mhh= mCa + mCao

9,6 = 4 + m CaO

m CaO = 5,6 gam

a) % mCa=4/9,6×100

=41,667%

% mCaO=5,6/9,6×100

= 58,333%

b)

n CaO=5,6/56=0,1 mol

nCaO=nCa(OH)2=0,1

m Ca(OH)2= 0,2 ×74= 14,8 gam