14 carat gold has a purity of 58.3%. How
many moles of gold are in 138 grams of 14
carat gold?
Answer in units of moles.
mols = g/molar mass
Thank you!!
To determine the number of moles of gold in 138 grams of 14 carat gold, you need to use the concept of molar mass and the percentage purity of the gold.
1. Determine the molar mass of gold (Au): The molar mass of gold is approximately 197 grams/mol. You can find this information from the periodic table or online sources.
2. Calculate the mass of pure gold in the 14 carat gold: Since 14 carat gold has a purity of 58.3%, we need to find the mass of pure gold in 138 grams of the alloy. This can be done by multiplying 138 grams by the purity percentage:
Mass of pure gold = 138 grams * (58.3/100) = 80.494 grams
3. Convert the mass of pure gold to moles: To convert grams to moles, you need to divide the mass by the molar mass. In this case, divide the mass of pure gold by the molar mass of gold:
Moles of gold = Mass of pure gold / Molar mass of gold
Moles of gold = 80.494 grams / 197 grams/mol
Moles of gold ≈ 0.408 moles
Therefore, there are approximately 0.408 moles of gold in 138 grams of 14 carat gold.