Question

If a chemist has 2.3 moles of arsenic (as) that has a molar mass of 74.92 g/mol, which would be the best way to find out how many atoms of arsenic are in the sample? multiply 2.3 by avogadro's number. divide 2.3 by avogadro's number. multiply 2.3 by the molar mass of arsenic. divide 2.3 by the molar mass of arsenic.

Answer 1

The best way to determine the number of atoms of arsenic in the sample will be to multiply 2.3 by Avagadro's number.
This is because Avagadro's number is the number of particles one mole of any substance has, and its value is 6.02 x 10²³
If the number of moles of a substance are known, then multiplying by Avagadro's number will give the number of particles. In this case, this is 1.38 x 10²⁴.