A solution of sodium hydroxide is standardized against potassium hydrogen phthalate (KHP, formula weight 204.2 g/mol). From
the following data, calculate the molarity of
the NaOH solution: mass of KHP 2.414 g;
buret reading before titration 0.23 mL; buret
reading after titration 39.67 mL.
Answer in units of M.

)benzene and toluene form nearly ideal solutions. consider an equimolar solution of benzene and toluene. at 20 °c the vapour pressures of pure benzene and toluene are 9.9 kpa and 2.9 kpa, respectively. the solution is boiled by reducing the external pressure below the vapour pressure. calculate (i) the pressure when boiling begins, (ii) the composition of each component in the vapour, and (iii) the vapour pressure when only a few drops of liquid remain. assume that the rate of vaporization is low enough for the temperature to remain constant at 20 °c.