Q3.131CP - Chemistry: Molecular Nature Of Matter And Change

Question

In each pair, choose the larger of the indicated quantities or state that the samples are equal: Mass: 6.02´10²³ atoms of ²³⁵U or 6.02´10²³ atoms of ²³⁸U

Step-by-Step Solution

Answer

The number of atoms is the same. More specifically they are exactly 1 mole, as the amounts of atoms equal to Avogadro’s number. Thus, the heavier is the one that has a larger molar mass. M of U²³⁵ = 235 g/mol, M of U²³⁸ Therefore, ²³⁸U has more grams.

Step1.Comparison.

The number of atoms is the same. More specifically they are exactly 1 mole, as the amounts of atoms equal to Avogadro’s number. Thus, the heavier is the one that has a larger molar mass. M of U²³⁵ = 235 g/mol, M of U²³⁸ Therefore, ²³⁸U has more grams.

Step2.Final Result.

The number of atoms is the same. More specifically they are exactly 1 mole, as the amounts of atoms equal to Avogadro’s number. Thus, the heavier is the one that has a larger molar mass. M of U²³⁵ = 235 g/mol, M of U²³⁸ Therefore, ²³⁸U has more grams.