When the volume of a gas is changed from 986 mL to mL,
the temperature will change from
765 K to 315 K.

THE NEW VOLUME OF THE GAS IS 406 mL WHEN THE TEMPERATURE CHANGES FROM 765 K TO 315 K.

Explanation:

When the temperature changes from  765 K to 315K, the volume has changed from 986 mL to?

V1 = 986 mL = 0.986 L

T1 = 765 K

T2 = 315 K

V2 = unknown

Using Charles' equation of gas laws;

V1 / T1 = V2 / T2

Making V2 the subject of the formula:

V2 = V1 T2 / T1

V2 = 0.986 * 315 / 765

V2 = 0.406 L

V2 = 406 mL

So therefore, the volume of a gas changes from 986 mL to 406 mL as a result of a change in temperature from 765 K to 315 K.

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