1. (a) C₂H₆ because it does not form H-bonds, unlike water
    (b) Li because it is smaller than Rn and therefore has less of an inducible dipole (London dispersion forces)
    (c) C₃H₈  same as (b)
    (d) HCl because it is not an ionically bonded salt like NaCl

2. (a) 50.0 g x 1 mole  x 22.4 L = 35 L
                        32 g       1 mole

    (b) 50.0 g x 1 mole x 6.02 x 10²³ g  = 9.4 x 10²³  molecules
                        32 g        mole

3. (a) 2H₂ + O₂  --> 2H₂O
    (b) For every 1 L H₂ you need 1 L H₂  x 1 L O₂  = 0.5 L O₂
                                                                   2 L H₂
            So we have excess oxygen and a limiting amount of hydrogen.
    (c) 1 L H₂ x 2 L H₂O  x 1 mole = 0.049 mole
                       2 L H₂        22.4 L