A typical penny has a mass of approximately 2.5 g and is primarily composed of copper. How many moles of copper atoms are present in a penny with a mass of 2.5 g? (Atomic mass of Cu = 63.55 g/mol)

• A. 0.039 moles
• B. 0.16 moles
• C. 0.25 moles
• D. 0.004 moles

Answer: (A)

Verified step by step guidance

1. Identify the given information: the mass of the penny is 2.5 g and the atomic mass of copper (Cu) is 63.55 g/mol.
2. Recall the formula to calculate moles from mass: \(\text{moles} = \frac{\text{mass}}{\text{molar mass}}\).
3. Substitute the given values into the formula: \(\text{moles of Cu} = \frac{2.5\ \text{g}}{63.55\ \text{g/mol}}\).
4. Perform the division to find the number of moles of copper atoms in the penny (do not calculate the final value here).
5. Interpret the result as the amount of copper atoms in moles present in the penny.