Questions: A copper atom has a mass of 1.06 x 10^-22 g and a penny has a mass of 2.5 g. Use this information to answer the questions below. Be sure your answers have the correct number of significant digits. What is the mass of 1 mole of copper at: 63.8 g How many moles of copper atoms have mass of a penny?

Solution Steps

The mass of 1 mole of copper is given as 63.8 g. This is the molar mass of copper, which is the mass of Avogadro's number of copper atoms (approximately \(6.022 \times 10^{23}\) atoms).

To find out how many moles of copper atoms are in a penny, we use the formula:

\[ \text{Number of moles} = \frac{\text{mass of the penny}}{\text{molar mass of copper}} \]

Given:

• Mass of the penny = 2.5 g
• Molar mass of copper = 63.8 g/mol

Substitute these values into the formula:

\[ \text{Number of moles} = \frac{2.5 \, \text{g}}{63.8 \, \text{g/mol}} \approx 0.0392 \, \text{mol} \]

Final Answer