1.CO2=100+7.5-105.3=2.2g=0.05mol2.总CaCO3=7.5/100=0.075mol>0.05mol代表CaCO3过量,盐酸充分反应CaCO3+2HCl=CaCl2+CO2+H2OHCl=2 ,,,,,,CO2=1HCl=xmol,CO2=0.052*0.05=x*1解得x=0.1molw=0.1*(35.5+1)/100*100%=3.65%