Problem 32 - Chemistry and Chemical Reactivity

Question

Calculate the molar mass of each of the following compounds: (a) \(\mathrm{Fe}\left(\mathrm{C}_{6} \mathrm{H}_{11} \mathrm{O}_{7}\right)_{2},\) iron \((\mathrm{II})\) gluconate, a dietary supplement (b) \(\mathrm{CH}_{3} \mathrm{CH}_{2} \mathrm{CH}_{2} \mathrm{CH}_{2} \mathrm{SH},\) butanethiol, has a skunk-like odor (c) \(\mathrm{C}_{20} \mathrm{H}_{24} \mathrm{N}_{2} \mathrm{O}_{2},\) quinine, used as an antimalarial drug

Step-by-Step Solution

Answer

(a) 446.146 g/mol, (b) 90.19 g/mol, (c) 324.412 g/mol

Step 1: Understand the Formula

For each compound provided, identify the elements and their respective quantities.

Step 2: Gather Atomic Masses

Use the periodic table to find the atomic masses: \ \( \text{Fe} = 55.85 \, \text{g/mol}, \, \text{C} = 12.01 \, \text{g/mol}, \, \text{H} = 1.008 \, \text{g/mol}, \, \text{O} = 16.00 \, \text{g/mol}, \, \text{S} = 32.07 \, \text{g/mol}, \, \text{N} = 14.01 \, \text{g/mol} \) .

Step 3: Calculate Molar Mass of Iron (II) Gluconate

For \( \mathrm{Fe}(\mathrm{C}_{6} \mathrm{H}_{11} \mathrm{O}_{7})_{2} \): - Fe: \(1 \times 55.85 = 55.85\)- C: \(6 \times 2 \times 12.01 = 144.12\)- H: \(11 \times 2 \times 1.008 = 22.176\)- O: \(7 \times 2 \times 16.00 = 224.00\)Add the masses: \[ 55.85 + 144.12 + 22.176 + 224.00 = 446.146 \, \text{g/mol} \]

Step 4: Calculate Molar Mass of Butanethiol

For \( \mathrm{C}_{4} \mathrm{H}_{10} \mathrm{S} \): - C: \(4 \times 12.01 = 48.04\)- H: \(10 \times 1.008 = 10.08\)- S: \(1 \times 32.07 = 32.07\)Add the masses: \[ 48.04 + 10.08 + 32.07 = 90.19 \, \text{g/mol} \]

Step 5: Calculate Molar Mass of Quinine

For \( \mathrm{C}_{20} \mathrm{H}_{24} \mathrm{N}_{2} \mathrm{O}_{2} \):- C: \(20 \times 12.01 = 240.20\)- H: \(24 \times 1.008 = 24.192\)- N: \(2 \times 14.01 = 28.02\)- O: \(2 \times 16.00 = 32.00\)Add the masses: \[ 240.20 + 24.192 + 28.02 + 32.00 = 324.412 \, \text{g/mol} \]

Step 6: Conclusion

The molar masses are as follows: (a) Iron (II) gluconate: 446.146 g/mol (b) Butanethiol: 90.19 g/mol (c) Quinine: 324.412 g/mol

Key Concepts

Chemical Compounds

Chemical compounds are pure substances formed by the combination of two or more elements. They are characterized by specific chemical formulas which provide insights into the types and numbers of atoms bound together in a molecule. For example, the chemical formula of iron (II) gluconate is \( ext{Fe(C}_6 ext{H}_{11} ext{O}_7)_2 \). Each formula is unique and reveals much about the compound's properties and potential uses. A compound's structure determines its reactivity, function, and role in various applications, like dietary supplements or medications.

Atomic Masses

Atomic mass refers to the mass of an atom, usually expressed in atomic mass units (amu). It represents the average mass of atoms of an element, considering the relative abundance of isotopes. The atomic masses of elements are crucial for calculating the molar mass of compounds. For instance, carbon has an atomic mass of 12.01 g/mol and oxygen has an atomic mass of 16.00 g/mol. By knowing these values, you can determine the total mass of atoms within a compound and thereby calculate its molar mass.

Periodic Table

The periodic table is an organized representation of all known elements, arranged based on increasing atomic number. It provides essential information like atomic number, element symbol, and atomic mass. This tool is indispensable in chemistry for understanding the relationships between elements. When you need to calculate molar masses, the periodic table is your go-to source for the atomic masses of each element. This information helps in balancing chemical equations and performing various chemical calculations effectively.

Iron (II) Gluconate

Iron (II) gluconate is a chemical compound often used as an iron supplement in the dietary realm. Its formula is \( ext{Fe(C}_6 ext{H}_{11} ext{O}_7)_2 \), indicating that it contains two gluconate ions for every iron ion. The gluconate ion is composed of carbon, hydrogen, and oxygen atoms, while the iron contributes to the compound's metallic properties. Iron (II) gluconate is valued for its ability to improve iron levels in the body, aiding in the prevention of anemia. Understanding its composition is crucial for determining its molar mass, which is around 446.146 g/mol.

Butanethiol

Butanethiol, with the chemical formula \( ext{C}_4 ext{H}_{10} ext{S} \), is a type of thiol that is notable for its potent, unpleasant skunk-like odor. Comprising of carbon, hydrogen, and sulfur, this compound is used in various industrial applications, often as an odorant to detect gas leaks. Despite its smell, it is an important chemical in the study of organosulfur compounds. Calculating the molar mass of butanethiol—90.19 g/mol—involves adding the individual atomic masses of its elemental components.

Quinine

Quinine is an alkaloid with the chemical formula \( ext{C}_{20} ext{H}_{24} ext{N}_2 ext{O}_2 \). Recognized for its use as an antimalarial drug, it has also found purposes in treating leg cramps and as a flavoring agent in tonic water. Quinine's structure allows it to impact disease-causing organisms, making it a crucial component in therapeutic treatments. To calculate its molar mass, which is about 324.412 g/mol, you add the atomic masses of the carbon, hydrogen, nitrogen, and oxygen atoms present in the compound.