To solve this question we need to know the mole concept. As we know that,
1 mole = 6.022 X 10^23 "molecules"
And we also know that the molar mass of H_2SO_4 is 98.079 g/mol which means:
1 mole of H_2SO_4 = 98.079 g
By using the above two relations, we get:
6.022 X 10^23 "molecules" of H_2SO_4 = 98.079 g of H_2SO_4
or, 1 "molecules" of H_2SO_4 = frac(98.079 )(6.022 X 10^23) g of H_2SO_4
or , 2.4X10^24 "molecules" of H_2SO_4 = frac(98.079)(6.022 X 10^23) X 2.4X10^24 g of H_2SO_4 = 390.88 g of H_2SO_4
Therefore, 2.4X10^24 "molecules" of H_2SO_4 contain 390.88 grams of H_2SO_4.