Calculate the number of moles in 74.1 g Pb(C2H3O2)2.
The molar mass is 325.28804 g/mol. Divide the amount given by the molar mass and that is your # moles.
Answer is .2278 moles
I agree with 0.2278 mols; however, you are limited to 3 significant figures by the 74.1 number; therefore it should be rounded to 0.228 mols.
To calculate the number of moles in a given substance, you need to use the formula:
moles = mass / molar mass
First, let's calculate the molar mass of Pb(C2H3O2)2 by adding up the atomic masses of its constituent elements.
The atomic masses are:
Pb (lead) = 207.2 g/mol
C (carbon) = 12.01 g/mol (there are 2 carbon atoms)
H (hydrogen) = 1.01 g/mol (there are 4 hydrogen atoms)
O (oxygen) = 16.00 g/mol (there are 4 oxygen atoms)
Now, let's calculate the molar mass:
molar mass = 207.2 + 2 * (12.01) + 3 * (1.01) + 2 * (16.00)
molar mass = 207.2 + 24.02 + 3.03 + 32.00
molar mass = 266.25 g/mol
Now that we have the molar mass, we can calculate the number of moles.
moles = mass / molar mass
moles = 74.1 g / 266.25 g/mol
moles = 0.278 mol
Therefore, there are approximately 0.278 moles in 74.1 g of Pb(C2H3O2)2.