When naming covalent compound both the first and second element in the fomula always receive a prefix to represent the number of each element present in the chemical formula.

Yes.

Explanation:

Yes,  both the first and second element in the formula of covalent compound always receive  a prefix to represent the number of each element present in the formula in order to show the percentage or proportion of each element in the formula of covalent compound. Prefix refers to  addition of word, letter, or number at the beginning of something so here number placed in front of element indicates the prefix.

just did the assignment and the answer was #1 +2 n

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