Question

混合碱试样0.6839克,用0.2mol/LHCL标准溶液滴定至终点,用酸溶液23.1ml,求Na2co3的百分含量

Answer 1

设混碱中含Na2CO3 x mol,NaHCO3 y mol

Na2CO3+HCl=NaHCO3+NaCl NaHCO3+HCl=Na2CO3+NaCl

x x x x+y x+y

x=23.1*0.2=4.61 mmol x+y=26.81*0.2=5.362 mmol y=5.362-4.61=0.752 mmol

Na2CO3含量为：4.61*106/1000/0.6839*100%=71.45%

NaHCO3含量为：0.752*84/1000/0.6839*100%=9.24%