How many moles are present in 10.0 mg of CO (carbon monoxide)?

• A. 3.57 × 10^{-4} mol
• B. 5.00 × 10^{-4} mol
• C. 2.50 × 10^{-4} mol
• D. 1.43 × 10^{-4} mol

Answer: (A)

Verified step by step guidance

1. Identify the given information: the mass of carbon monoxide (CO) is 10.0 mg. Convert this mass into grams because molar mass is typically in grams per mole. Use the conversion factor: 1 mg = 0.001 g.
2. Calculate the molar mass of CO by adding the atomic masses of carbon (C) and oxygen (O). Use the periodic table values: approximately 12.01 g/mol for carbon and 16.00 g/mol for oxygen. So, molar mass of CO = 12.01 + 16.00 g/mol.
3. Use the formula to find moles from mass and molar mass: \(\text{moles} = \frac{\text{mass (g)}}{\text{molar mass (g/mol)}}\).
4. Substitute the converted mass (in grams) and the molar mass of CO into the formula to set up the calculation for moles.
5. Perform the division to find the number of moles present in 10.0 mg of CO.