How many aluminum atoms are there in 15.0mg of Al2O3?
figure moles of alumium oxide first
moles=.015/molmassAl2O3
there are twice as many moles as that of aluminum atoms.
aluminum atoms=2*molesAl2O3*avagnumber
Thank you bobpursley!!!
To find the number of aluminum atoms in 15.0mg of Al2O3, we need to follow these steps:
1. Determine the molar mass of Al2O3 (aluminum oxide).
- Aluminum (Al) has a molar mass of 26.98 g/mol.
- Oxygen (O) has a molar mass of 16.00 g/mol.
- Since there are 2 aluminum atoms (Al) and 3 oxygen atoms (O) in Al2O3, the molar mass of Al2O3 is:
(2 * 26.98 g/mol) + (3 * 16.00 g/mol) = 101.96 g/mol.
2. Convert the given mass of Al2O3 to moles.
- Use the formula: moles = mass (in grams) / molar mass.
- Convert 15.0mg to grams by dividing by 1000: 15.0mg / 1000 = 0.015g.
- Now, calculate the number of moles: moles = 0.015g / 101.96 g/mol.
3. Determine the number of aluminum atoms.
- Since there are 2 aluminum atoms in 1 molecule of Al2O3, multiply the moles of Al2O3 by the Avogadro's number (6.022 x 10^23 atoms/mol):
aluminum atoms = moles of Al2O3 * (2 * 6.022 x 10^23 atoms/mol).
Performing the calculation:
moles of Al2O3 = 0.015g / 101.96 g/mol
aluminum atoms = (0.015g / 101.96 g/mol) * (2 * 6.022 x 10^23 atoms/mol)
Once you calculate the expression above, you will have the number of aluminum atoms in 15.0mg of Al2O3.