Question

How many moles are in 15.0 grams of calcium?


0.374 moles

2.67 moles

601.5 moles

2.40 x 1025 moles

Answer 1

There are 40.1 grams of Ca in 1 mole of Ca. So in 15.0 grams of Ca, there are 15/40.1 moles of Ca.\[15.0 \space g \space Ca \times \frac {1 \space mol \space Ca}{40.1 \space g \space Ca} \approx 0.374 mol\]

Answer 2

Approximately 0.374 moles.
Follow the steps of Rogue and get the answer.