2. What harmful change/s is/are brought about when a metal reacts or mixes with acids​

hydrogen gas

When metal reacts with acids it produces metal salt and hydrogen gas ( H2 ) . All metals do not react with acids to evolve hydrogen gas . Only those metals react which is more reactive than hydrogen . When metal reacts with acid it forms a salt which is basic in nature and releases hydrogen gas.

Explanation:

When metals react with other substances, the gradual wearing away or corrosion of a metal results.This may lead to deterioration of metals

the answer is option a.

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