m(CO2)=ρV=1.997*2.23=4.45g
CaCO3+2HCl=CaCl2=CaCl2+H2O+CO2↑
73 44
x 4.45g
x=73*4.45/44=7.38g
稀盐酸的溶质质量分数为7.38/100*100%=7.38%