Urgent help plsss a stock solution of 2M NaOH was prepared by dissolving 4g NaOH in 50cm³ of distilled water. 10cm³ of the stock solution was put into a measuring cylinder and then diluted with different amount of distilled water to 15cm³. determine the volume of distilled water used to dilute the solution. Calculate the concentration of the solution in mol/dm³ and g/dm³​

)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.