Chapter 9, Problem 12A

Interpretation Introduction

Interpretation:

The quantity which is a conversion factor between mass of sample and number of moles needs to be determined.

Concept Introduction: The number of moles is related to mass and molar mass. Molar mass is defined as the mass of 1 mol of a substance.

Answer to Problem 12A

Molar mass (g/mol)

Explanation of Solution

Consider a sample of a substance that weighs, 'm' grams and contains 'n' number of moles. The quantities- mass and moles are related by the following equation:

  $\begin{array}{l}\text{number of moles = }\frac{\text{Mass of the substance }}{\text{Molar mass of the substance}}\\ \text{'n' moles = }\frac{\text{'m' grams}}{\text{'M' grams/mol}}\end{array}$

Conclusion

Therefore, molar mass (M) which is the mass corresponding to 1 mole of the substance is the conversion factor between 'mass' and 'moles'.