Calculating Moles/Atoms/Mass

Question 1

Formula to convert moles to molecules/atoms/ions?

Answer 1

N = n(NA)

Question 1

What is N in N = n(NA)?

Answer 1

The number of objects (atoms, molecules, or ions)

Question 2

What is n in N = n(NA)?

Answer 2

The amount of moles (mol)

Question 3

What is NA in N = n(NA)?

Answer 3

Avogadro’s constant
(6.0221 * 10^23)

Question 4

Formula to find the amount of moles when mass is known?

Answer 4

n = m/M

Question 5

What is n in n = m/M?

Answer 5

The amount of moles (mol)

Question 6

What is m in n=m/M?

Answer 6

The mass (g)

Question 7

What is M in n = m/M?

Answer 7

The molar mass (g/mol)

Question 8

Can you determine the amount of atoms from the mass alone?

Answer 8

Yes, assuming the molar mass can be determined.
The amount of moles is calculated with n = m/M, then Avogadro’s constant can be used to determine the amount of atoms

Question 9

How can you calculate the average mass of isotopes?

Answer 9

You multiply the mass of each isotope by the abundance percentage, then add all of the sums together to get the average mass.

m(average) = f(isotope-1)*b(isotope-1) + f(isotope-2)*b(isotope-2)…