Blessy has four different solids. She investigates how many grams of each solid she can dissolve in water. Here is what she does • pours 20 cm3 of water into a beaker • adds 1 g of solid to the water and stirs • if the solid dissolves she adds another 1 g of solid and stirs • she keeps adding 1 g of solid at a time until no more dissolves. Here are her results. name of solid sugar16g fertiliser===30g salt8g baking powder5g (a) Blessy keeps the temperature of the water for each solid the same. Explain why. (b) Blessy thinks it is a good idea to repeat her investigation. Explain why.

answer : (a) volume of the gas = 8.67 ×   l

                (b) second virial coefficient b = -1.21226 l/mole

solution :   given,     t = 300k

                                p = 20atm

                                z = 0.86

                                n = 8.2 mmoles = 8.2 × moles

                                r =   0.082 l atm/k/mol

        find,     (a) volume of gas   and (b) second virial coefficient b at 300k.

formula used :            

                          and            

(a)            

                    = \times 0.082\times 300}{20}[/tex]

                    = 8.67 ×   l

(b)      

                    = (0.00867-1) × 8.659

                    = - 8.5839 l/mole