Chapter 6, Problem 4STP

Interpretation Introduction

Interpretation : The most accurate description of mole is to be stated.

Concept Introduction : Average atomic mass of an element has a number of atoms equivalent to Avogadro’s number. The latter is defined as the number of atoms of any element that are present in a sample that weighs equivalent to average atomic mass of element. The value of Avogadro’s number is $6.022\times {10}^{23}\text{particles}$ .

Answer to Problem 4STP

Correct answer: The correct option is A.

Explanation of Solution

Reason for correct option:The atomic mass of iron is $55.85\text{g/mol}$ . As one mole of an element is defined as the average atomic mass of element in grams, therefore, the number of atoms that are present in $55.85\text{g}$ of iron is equal to one mole.

Conclusion

Reasons for incorrect options:The atomic mass of carbon is $12.01\text{g/mol}$ . As one mole of an element is defined as the average atomic mass of element in grams, therefore, one mole of carbon corresponds to $12.01\text{g}$ . Therefore, option B does not accurately define mole. The number of atoms that are present in any given mass of molecule corresponds to one mole if the number of atoms corresponds to Avogadro’s number of atoms that is $6.022\times {10}^{23}\text{atoms}$ . Therefore, option C is incorrect. One mole of an element is equivalent to $6.022\times {10}^{23}\text{atoms}$ . Thus, option D could not accurately define mole.