Calculating Gold Atoms: Mole Concept and 15% Pure Gold Mass

In summary, to calculate the number of gold atoms in a given mass of 15% pure gold, we first need to determine the mass of pure gold in the sample by multiplying the total mass by the percentage of pure gold. Then, we convert this mass to moles using the molar mass of gold and use Avogadro's number to convert moles to the number of atoms. The mole concept is important in this calculation as it relates the mass of a substance to its number of particles. It is crucial to accurately determine the percentage purity of the sample in order to calculate the correct number of gold atoms. Other factors that can affect the accuracy of the calculation include experimental errors, variations in molar mass, and the presence of imp
  • #1
Kelly09
14
0
How many Gold atoms are in Gold mass of 2.5g? 15 percent of the mass is pure Gold.
So first i found 15 percent of the mass which i used to calculate the number of moles. Then i multiplied the moles by Avogadros number to give me the atoms. Anyone help
 
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  • #2
Not sure what kind of help you need - what you wrote sounds like a correct approach to the problem.

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  • #3


Based on the information provided, we can calculate the number of gold atoms in a gold mass of 2.5g using the mole concept. First, we need to calculate the mass of pure gold in 2.5g using the given percentage (15%):

Mass of pure gold = 15% x 2.5g = 0.375g

Next, we need to convert this mass into moles using the molar mass of gold (197g/mol):

Number of moles of pure gold = 0.375g / 197g/mol = 0.0019 mol

Finally, we can use Avogadro's number (6.022 x 10^23) to calculate the number of gold atoms in 0.0019 mol:

Number of gold atoms = 0.0019 mol x 6.022 x 10^23 = 1.142 x 10^21 gold atoms

Therefore, there are approximately 1.142 x 10^21 gold atoms in a gold mass of 2.5g, with 15% of the mass being pure gold.
 

1. How do you calculate the number of gold atoms in a given mass of 15% pure gold?

To calculate the number of gold atoms, we first need to determine the mass of pure gold in the given sample. This can be done by multiplying the total mass of the sample by the percentage of pure gold (15%). Next, we need to convert this mass to moles by dividing it by the molar mass of gold. Finally, we can use Avogadro's number (6.022 x 10^23) to convert moles to the number of atoms.

2. What is the mole concept and how is it related to calculating gold atoms?

The mole concept is a fundamental concept in chemistry that relates the mass of a substance to its number of particles. In the case of calculating gold atoms, we use the mole concept to convert the mass of 15% pure gold to moles, which allows us to determine the number of atoms present in the sample.

3. Can you explain the difference between percentage purity and percentage by mass?

Percentage purity refers to the amount of a specific substance present in a sample, while percentage by mass refers to the mass of a specific substance in a sample. In the case of calculating gold atoms, we use the percentage purity (15%) to determine the mass of pure gold in the sample, which is then used to calculate the number of gold atoms.

4. Why is it important to consider the purity of a sample when calculating the number of gold atoms?

The purity of a sample is important because it affects the mass of the substance present. In the case of 15% pure gold, if we do not take into account the percentage purity, our calculation for the number of gold atoms will be incorrect. It is important to use the correct percentage purity to accurately determine the mass of pure gold in the sample.

5. Are there any other factors that can affect the accuracy of calculating gold atoms?

Yes, there are several other factors that can affect the accuracy of calculating gold atoms. These include experimental errors, variations in the molar mass of gold, and the presence of impurities in the sample. It is important to carefully conduct the experiment and use accurate measurements to minimize these potential sources of error.

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