Chapter 14, Problem 115A

(a)

Interpretation Introduction

Interpretation: To calculate the molar mass of the given substance.

Concept Introduction: Molar mass is defined as the smallest unit of the compound. It is the $\frac{1}{12}\text{th}$ mass of the Carbon-12. Molar mass is defined as the sum of total mass in grams of all the atoms that make up a mole of the molecule.

Answer to Problem 115A

158 g/mol.

Explanation of Solution

The given molecular compound is ${\text{Ca(CH}}_3{\text{CO}}_{\text{2}}{)}_2$

There is only one calcium atom in the given compound. The molar mass of calcium atom is 40 g/mol.

There are six hydrogen atoms in the given compound. The molar mass of one hydrogen atom is 1 g/mol. Therefore, the molar mass of six hydrogen atoms will be $6\times 1\frac{\text{g}}{\text{mol}}=6\frac{\text{g}}{\text{mol}}$ .

There are four carbon atoms in the given compound. The molar mass of one carbon atom is 12 g/mol. Therefore, the molar mass of four carbon atoms will be $12\times 4\frac{\text{g}}{\text{mol}}=48\frac{\text{g}}{\text{mol}}$

There are four oxygen atoms in the given compound. The molar mass of one oxygen atom is 16 g/mol. Therefore, the molar mass of four oxygen atoms will be $16\times 4\frac{\text{g}}{\text{mol}}=64\frac{\text{g}}{\text{mol}}$ .

Therefore, the molar mass of the compound will be 158 g/mol.

(b)

Interpretation Introduction

Interpretation: To calculate the molar mass of the given substance.

Concept Introduction: Molar mass is defined as the smallest unit of the compound. It is the $\frac{1}{12}\text{th}$ mass of the Carbon-12. Molar mass is defined as the sum of total mass in grams of all the atoms that make up a mole of the molecule.

Answer to Problem 115A

98 g/mol

Explanation of Solution

There are three hydrogen atoms in the given compound. The molar mass of one hydrogen atom is 1 g/mol. Therefore, the molar mass of three hydrogen atoms will be $3\times 1\frac{\text{g}}{\text{mol}}=3\frac{\text{g}}{\text{mol}}$

There is only one phosphorous atom in the given compound. The molar mass of Phosphorous atom is 31 g/mol.

There are four oxygen atoms in the given compound. The molar mass of one oxygen atom is 16 g/mol. Therefore, the molar mass of four oxygen atoms will be $16\times 4\frac{\text{g}}{\text{mol}}=64\frac{\text{g}}{\text{mol}}$ .

The overall molar mass of the compound will be 98 g/mol

(c)

Interpretation Introduction

Interpretation: To calculate the molar mass of the given substance.

Concept Introduction: Molar mass is defined as the smallest unit of the compound. It is the $\frac{1}{12}\text{th}$ mass of the Carbon-12. Molar mass is defined as the sum of total mass in grams of all the atoms that make up a mole of the molecule.

Answer to Problem 115A

342 g/mol.

Explanation of Solution

There are twelve carbon atoms in the given compound. The molar mass of one carbon atom is 12 g/mol. Therefore, the molar mass of twelve carbon atoms will be $12\times 12\frac{\text{g}}{\text{mol}}=144\frac{\text{g}}{\text{mol}}$

There are 22 hydrogen atoms in the given compound. The molar mass of one hydrogen atom is 1 g/mol. Therefore, the molar mass of 22 hydrogen atoms will be $22\times 1\frac{\text{g}}{\text{mol}}=22\frac{\text{g}}{\text{mol}}$

There are eleven oxygen atoms in the given compound. The molar mass of one oxygen atom is 16 g/mol. Therefore, the molar mass of eleven oxygen atoms will be $16\times 11\frac{\text{g}}{\text{mol}}=176\frac{\text{g}}{\text{mol}}$

The overall molar mass of the compound will be 342 g/mol.

(d)

Interpretation Introduction

Interpretation: To calculate the molar mass of the given substance.

Concept Introduction: Molar mass is defined as the smallest unit of the compound. It is the $\frac{1}{12}\text{th}$ mass of the Carbon-12. Molar mass is defined as the sum of total mass in grams of all the atoms that make up a mole of the molecule.

Answer to Problem 115A

331 g/mol

Explanation of Solution

There is one lead atom in the given compound. The molar mass of the lead atom is 207 g/mol.

There are two nitrogen atoms in the given compound. The molar mass of one nitrogen atom is 14 g/mol. Therefore, the molar mass of the two nitrogen atoms will be $14\times 2\frac{\text{g}}{\text{mol}}=28\frac{\text{g}}{\text{mol}}$

There are six oxygen atoms in the given compound. The molar mass of one oxygen atom is 16 g/mol. Therefore, the molar mass of six oxygen atoms will be $16\times 6\frac{\text{g}}{\text{mol}}=96\frac{\text{g}}{\text{mol}}$ .

The overall molar mass of the given compound will be 331 g/mol