i'm so confused with how to do these someone please help
calculate the number of moles in each of the following masses
a)64.1 g of aluminum
b)28.1 g of silicon
c)0.255 g of sulfur
d)850.5 g of zinc
64.1 divided by the atomic mass of aluminum = answer
To calculate the number of moles in each of the given masses, we need to use the concept of molar mass and the formula:
moles = mass (in grams) / molar mass
The molar mass of an element or a compound is the mass of one mole of that substance expressed in grams/mol.
Let's calculate the number of moles for each given mass:
a) 64.1 g of aluminum:
The molar mass of aluminum (Al) is 26.98 g/mol.
moles = 64.1 g / 26.98 g/mol
moles ≈ 2.374 mol
b) 28.1 g of silicon:
The molar mass of silicon (Si) is 28.09 g/mol.
moles = 28.1 g / 28.09 g/mol
moles ≈ 1.0003 mol
c) 0.255 g of sulfur:
The molar mass of sulfur (S) is 32.07 g/mol.
moles = 0.255 g / 32.07 g/mol
moles ≈ 0.007956 mol
d) 850.5 g of zinc:
The molar mass of zinc (Zn) is 65.38 g/mol.
moles = 850.5 g / 65.38 g/mol
moles ≈ 13.009 mol
Therefore, the number of moles for the given masses are:
a) 2.374 mol
b) 1.0003 mol
c) 0.007956 mol
d) 13.009 mol
mols = grams/atomic mass.
Just look up the atomic mass on the periodic table, plug in the number and grams, and calculate. Piece of cake. Nothing to be confused about.