Question

The molar mass of phosphorus is equal to the mass of 6.02 x 1023 atoms of phosphorus. What is the molar mass of phosphorus, in g/mol?

5.14
30.97
45.97
90.33

Answer 1

The molar mass of phosphorus is 30.97 g/mol, which is the atomic mass of phosphorus and equivalent to the mass of 6.02 x 10^23 atoms of phosphorus.

Step-by-step explanation:

The molar mass of an element is defined as the mass of one mole of representative particles of a substance. The mass, in grams, of 1 mole of particles of a substance is referred to as the molar mass, and it is numerically equal to the atomic mass of the element when expressed in grams. Given that 6.02 x 1023 atoms of phosphorus represents one mole of phosphorus, the molar mass of phosphorus is the mass of this many atoms. Therefore, the correct molar mass of phosphorus, in grams per mole (g/mol), is 30.97 g/mol, as this is the atomic mass of phosphorus as found in the periodic table.

Answer 2

If we look at the periodic table, we see that phosphorous has an atomic mass of 30.97. Therefore, it has a molar mass of 30.97 g/mol. The answer is B.