Answer:
1) 16.0 moles Al
24.0 moles S
96.0 moles O
2)In 6.10 moles magnesium perchlorate, (Mg(CIO4)2 we have:
6.10 moles Mg
12.2 moles Cl
48.8 moles O
3)4.6 moles of propane (total) contains 13.8 moles of carbon and 36.8 moles of hydrogen atoms
4)The gold coin contains 7.8 *10^22 atoms
Explanation:
Step 1: Data given
Number of moles of aluminum sulfate, Al2(SO4)3 = 8.00 moles
Step 2: Calculate the number of moles
In 1 mol of aluminum sulfate, Al2(SO4)3 we have:
2 moles of Al
3 moles of S
12 moles of O
This means that in 8.00 moles of aluminum sulfate, Al2(SO4)3 we have:
2*8.00 = 16.0 moles Al
3*8.00 = 24.0 moles S
12*8 = 96.0 moles O
2. Calculate the number of moles of magnesium, chlorine, and oxygen atoms in 6.10 moles of magnesium perchlorate, (Mg(CIO4)2
1 mol of magnesium perchlorate, (Mg(CIO4)2 has:
1 Mol of Mg
2 moles of Cl
8 moles of O
In 6.10 moles magnesium perchlorate, (Mg(CIO4)2 we have:
1 * 6.10 moles = 6.10 moles Mg
2*6.10 = 12.2 moles Cl
8*6.10 = 48.8 moles O
3. A sample of propane, C3H8, contains 13.8 moles of carbon atoms. How many total moles of atoms does the sample contain?
In 1 mol of propane, C3H8 we have:
3 moles of C and 8 moles of H
This means if we have 13.8 moles of carbon, we have 13.8/3 = 4.6 moles of propane, C3H8 and 4.6 *8 = 36.8 moles of H
So 4.6 moles of propane contains 13.8 moles of carbon and 36.8 moles of hydrogen atoms
4. A rare gold coin (24 karat, or 100% gold) has a mass of 25.54 g. How many atoms of gold are present in this coin?
Calculate moles of gold:
Moles = mass of gold / molar mass gold
Moles = 25.54 grams / 196.97 g/mol
Moles = 0.1297 moles
Calculate atoms:
Number of atoms = moles * number of Avogadro
0.1297 * 6.022 *10^23 = 7.8 *10^22 atoms
The gold coin contains 7.8 *10^22 atoms
