Question & Answer: How many kilograms of phosphorous are in a sample containing 2.50E+30 phosphorous…..

phosphorous molecular wt = 30.97 g/mole

1 mole of phosphorous contains = 6.022 x 10²³ phosphorous atoms (Avogadro’s number) = 30.97 g

We need to calculate the weight of 2.50x 10³⁰ phosphorous atoms.

Weight of the sample = (2.50x 10³⁰ atoms x 30.97 g)/6.022 x 10²³ atoms = 1.286 x 10⁸ g = 1.286 x 10⁵ Kg

The answer is 1.286 x 10⁵ Kg of phosphorous.(three significant figures)