Moles of iron = 7.30
<h3>Further explanation</h3>
Given
mass of iron = 408.67 g
Required
moles of atoms
Solution
The mole is the number of particles contained in a substance
1 mol = 6.02.10²³
Moles can also be determined from the amount of substance mass and its molar mass
mol iron-Fe (Ar = 56 g/mol)
mol = mass : MW
mol = 408.67 g : 56
mol = 7.30
The answer is c I know because I did did yesterday
B. Intake valve is the correct answer
The answer is 0.5010
Number of moles (n) is equal to the quotient of mass (m) and molar mass of a sample (Mr):
n = m/Mr
We have:
n = ?
m = 40.10 g
Mr = 80.0432 g/mol
n = 40.10 g : 80.0432 g/mol = 0.5010
<span>40.10 has 4 significant digits,
</span><span>80.0432 has 6 significant digits.
Since 4 is less than 6, we choose 4 </span>significant digits