The mass % of Ca in CaSO4 is 29.45%. To calculate the mass of Ca present in a 25.6-g sample of this compound, the correct procedure is given by .

The correct answer is - 29.45 / 100 x 25.6 = 7.5392 grams

Explanation:

It is given in the question that in 100 gms of CaSO4 there are 29.45 grams of Ca present and there is 25.6 gram of total CaSO4 sample present, So, to calculate the exact value of calcium in this given sample is:

mass of Ca = total amount of sample*percentage of calcium in sample /100

M of Ca =25.6*29.45/100

M of Ca = 7.5392 grams

Thus, the correct procedure is given by 29.45 / 100 x 25.6 = 7.5392 grams

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