`alpha`-D-glucopyranose reacts with periodate ion as follows:
`C_(6)H_(12)O_(6)(aq)+IO_(4)^(-)(aq) to HCOOH(aq)+HCHO(aq)+IO_(3)^(-)(aq)`
In a typical experiment, a 1 mL solution of `alpha`-D-Glucopyranose required 80mL 0.25 M periodate solution to reach the equivalence point. The solution is made free from formic acid and iodate ion by extraction and then treated with `H_(2)O_(2)`, an oxidizing agent, oxidizing all formaldehyde into formic acid and finally titrated against 0.1 M NaOH solution. Titration required 40 mL of alkali to reach the equivalance point. Determine molarity of `alpha`-D-glucpyranose solution.

Answer

4