Final answer:
To find a substance with the same mass as 0.25 mol of copper atoms, we look for a substance where 0.25 mol weighs 16 grams. Since 0.5 mol of sulfur has a mass of 16 grams, 0.5 mol of sulfur atoms has the same mass as 0.25 mol of copper atoms.
Step-by-step explanation:
The student is asking about the mass equivalence of 0.25 mol of copper atoms. Since copper (Cu) has an atomic mass of 64 grams per mole, 0.25 mol would have a mass of:
0.25 mol x 64 g/mol = 16 g
To find a substance with the same mass as 0.25 mol of copper, we just need to find a substance where 0.25 mol of that substance also weighs 16 grams.
Since the atomic or molecular mass of a substance determines the mass of 1 mole of that substance, we can use the atomic masses provided for hydrogen (H), oxygen (O), and sulfur (S) to create compounds or elemental masses that also weigh 16 grams per 0.25 mol.
Here are examples:
- For water (H2O), which has a molar mass of approximately 18 g/mol: 0.25 mol x 18 g/mol = 4.5 g, so this is not equivalent.
- For sulfur (S), which has a molar mass of 32 g/mol: 0.25 mol x 32 g/mol = 8 g, so this is also not equivalent.
- If we were to consider 0.5 mol of sulfur, however, since 0.5 mol x 32 g/mol = 16 g, this would be the equivalent mass to 0.25 mol of copper atoms.
Therefore, 0.5 mol of sulfur atoms would have the same mass as 0.25 mol of copper atoms.