Question

1.How many copper atoms are in a pure copper statue with a mass of 191 kg ?Express your answer to three significant figures.

2.What is the mass in grams of each elemental sample?
1. 6.66 mol W
2. 0.586 mol Ba
3. 68.5 mol Xe
4.1.58 mol S
3.
How many mercury atoms are in 7.3 mol of mercury? Express your answer in atoms to two significant figures.

Answer 1

To calculate the number of copper atoms in a pure copper statue with a mass of 191 kg, we need to use the molar mass of copper and Avogadro's number. For the second question, we can use the formula Number of atoms = moles x Avogadro's number to calculate the number of mercury atoms in 7.3 mol.

Step-by-step explanation:

To calculate the number of copper atoms in a pure copper statue with a mass of 191 kg, we need to use the molar mass of copper and Avogadro's number. The molar mass of copper is 63.5 g/mol. We can start by converting the mass of the statue from kilograms to grams:

191 kg = 191,000 g

Next, we can use the molar mass to convert grams to moles:

191,000 g / (63.5 g/mol) = 3006.29 mol

Finally, we can use Avogadro's number to convert moles to atoms:

3006.29 mol * 6.022 x 10^23 atoms/mol =
`1.81 x 10^{27` atoms

Therefore, there are approximately
`1.81 x 10^{27` copper atoms in the pure copper statue.

For the second question, we can use the formula

Number of atoms = moles x Avogadro's number

to calculate the number of mercury atoms in 7.3 mol:

7.3 mol x 6.022 x
`10^{23` atoms/mol = 4.39 x
`10^{24` atoms

Therefore, there are approximately 4.39 x
`10^{24` mercury atoms in 7.3 mol of mercury.

Answer 2

The pure copper statue weighing 191 kg contains approximately 1.81 × 10²¸ copper atoms, calculated using the atomic mass of copper and Avogadro's number.

Step-by-step explanation:

To determine how many copper atoms are in a 191 kg pure copper statue, we must use the atomic mass of copper and Avogadro's number. Given that the atomic mass of copper is approximately 63.5 g/mol, we first convert the mass of the statue to grams (191 kg x 1000 g/kg = 191000 g) and then calculate the number of moles of copper in the statue:

191000 g Cu × (1 mol Cu / 63.5 g Cu) = 3007.87 mol Cu.

Now that we have the number of moles of copper, we can multiply it by Avogadro's number (6.022 × 10²³ atoms/mol) to get the number of copper atoms:

3007.87 mol Cu × (6.022 × 10²³ atoms/mol) = 1.81 × 10²¸ Cu atoms.

To express the answer to three significant figures, we have approximately 1.81 × 10²¸ copper atoms in the statue.