需要m(HCl浓)=300*0.1=30gm（38%的稀盐酸)=30/0.38=78.95gV（38%的稀盐酸)=78.95/1=78.95mlV(H2O)=300-78.95=221.05mL
m(HCl浓)=300*10%/38%=78.95gV(H2O)=300-78.95=221.05mL
