Since we are given the amount of moles of each element,
to calculate for the mass we need to remember that:
Mass = Molar mass * Moles
Moles = Atom / (6.022*10^23 atoms / mole)
6.022*10^23 atoms / mole is the Avogadro’s constant to
convert atoms to moles.
So when atoms are given: Mass = Molar mass * Atom /
6.022*10^23
Searching for the molar mass of each element in the
periodic table:
Iron (Fe) = 55.85 g / mol
Silver (Ag) = 107.87 g / mol
Lead (Pb) = 207.2 g / mol
Hydrogen (H) = 1 g / mol
Therefore calculating for the
mass:
A. Mass of Fe = (55.85 g /
mol) * 0.3 mol
Mass of Fe = 16.76 g
B. Mass of Ag = (107.87 g /
mol) * 1 atom / (6.022*10^23 atoms / mole)
Mass of Ag = 1.8 * 10^-22 g
C. Mass of Pb = (207.2
g / mol) * 25 atom / (6.022*10^23 atoms
/ mole)
Mass of Pb = 8.6 * 10^-21 g
D. Mass of H = (1 g / mol) *
1 mol
Mass of H = 1 g
Therefore 0.3 mol of iron
has the greatest mass among the 4 elements.
Answer: 0.3 mol of iron Fe
