Calculate the pH of a solution prepared by dissolving 0.15 mol benzoic acid (C7H5O2H) and 0.30 mol of sodium benzoate (Na C7H5O2) in water sufficient to yield 1.00 L of solution. The Ka of benzoic acid is 6.50 x 10-5

13. a covalent bond between two atoms is likely to be polar if: a. one of the atoms is much more electronegative than the other. b. the two atoms are equally electronegative. c. the two atoms are of the same element. d. the bond is part of a tetrahedrally shaped molecule. e. one atom is an anion.

)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.

How many neutrons does an element have if its atomic number is 50 and its mass number is 166