Question
A solution contains Na2CO3 and NaOH. Using phenolphthalein as an indicator, 25 mL of a mixture requires 19.5 mL of 0.005 N HCl for the end point. If methyl orange is the indicator, then 25 mL of the solution requires 25.9 of the same HCl for end point. The concentration of NaOH substance in g per litre is (write it as 0.23=2 (only single digit)) :