解:m(CaCo3)=m(总)-m(杂) =2g-0.3g =1.7g注:因为是充分反应,所以剩下的0.3克就是杂质质量CaCo3%=1.7g/2g*100% =85%50吨中含杂质50t*15%=7.5t设CaCo3质量为x.CaCo3=高温=== CaO+CO2↑100 5642.5 xx=23.8t含杂质的生石灰为23.8t+7.5t=31.3t.