1、M co2=150g+7.2g-155g=2.2g
2、设Caco3质量为x
CaCO3+2Hcl=Cacl+H20+Co2↑
100 44
x 2.2g
100/x=44/2.2g
x=5g
CaCO3%=5g/7.2g≈69.4%
答: