14 carat gold has a purity of 58.3%. How
many moles of gold are in 172 grams of 14
carat gold?
Answer in units of moles
g Au = 172 x 0.583 = ?
Then mols = grams/atomic mass
I got 100.276. Do i divide that by 172?
No, mols = grams/atomic mass Au.
100.276/196.966 = ?
Watch the number of significant digits; especially if your prof is picky about that OR if you are typing these answers into a database.
To calculate the number of moles of gold in 172 grams of 14 carat gold, we need to use the molar mass of gold and convert the given mass into moles. Here's how you can do it:
1. Find the molar mass of gold:
The molar mass of gold (Au) can be found on the periodic table, which is approximately 197 grams per mole.
2. Calculate the mass of pure gold in 172 grams of 14 carat gold:
Since 14 carat gold has a purity of 58.3%, it means that 58.3% of the total mass is pure gold. So, we multiply the given mass by the purity percentage:
Mass of pure gold = 172 grams × (58.3 ÷ 100) = 100.236 grams
3. Convert the mass of pure gold into moles:
Now, we can convert the mass of pure gold into moles using the molar mass:
Moles of gold = Mass of pure gold / Molar mass of gold
Moles of gold = 100.236 grams / 197 grams per mole
Moles of gold ≈ 0.508 moles (rounded to three decimal places)
Therefore, there are approximately 0.508 moles of gold in 172 grams of 14 carat gold.