Suppose that a substance in a beaker is heated over a burner in a science lab. Which observation would most likely indicate that a chemical change has occurred in the substance? 1) If the substance is a liquid or solid, an increase in temperature would indicate a chemical change.

2) If the substance is a liquid, a change of some of the liquid to gaseous form would indicate a chemical change.

3) If the substance is a solid, a change of some of the solid to liquid form would indicate a chemical change.

4) If the substance is a liquid or solid, the production of an odor would indicate a chemical change.

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