How many moles of Magnesium are present in 0.478 g of the element?
(Atomic mass: Mg-24 u)

0.0199moles

Explanation:

The number of miles of a substance can be calculated using the formula:

Number of moles (n) = Mass (M) / Molar mass (MM)

In this question, the mass of Magnesium element (Mg) = 0.478 g while the atomic mass is 24

Therefore, number of moles of Magnesium is:

Moles = 0.478/24

Moles = 0.01992

Hence, 0.0199 moles of Magnesium are contained in 0.478 g of the element.

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