Answer: Molar mass of ethanol (C2H5OH) is 46.07 g/mol.
Molar Mass of Ethanol
Ethanol (C2H5OH) is a common alcohol used in beverages, antiseptics, and as a solvent or fuel. It consists of two carbon (C) atoms, five hydrogen (H) atoms, one oxygen (O) atom, and one hydroxyl group (OH). The molar mass of ethanol is a crucial value in chemistry, especially in applications like combustion reactions, alcoholic fermentation, and other industrial processes.
In this guide, we will calculate the molar mass of ethanol and explain its significance in various chemical processes.
Understanding Molar Mass
Molar mass refers to the mass of one mole of a substance, expressed in grams per mole (g/mol). One mole contains \(6.022 \times 10^{23}\) molecules, atoms, or ions, also known as Avogadro’s number. The molar mass is essential for converting between the mass of a substance and the number of moles in chemical reactions and stoichiometry.
To calculate the molar mass of ethanol (C2H5OH), we need to know the molar masses of its constituent atoms: carbon (C), hydrogen (H), and oxygen (O).
Molar Masses of Carbon, Hydrogen, and Oxygen
To calculate the molar mass of ethanol, we first need to know the molar masses of its atoms:
- Carbon (C): The molar mass of carbon is approximately 12.01 g/mol.
- Hydrogen (H): The molar mass of hydrogen is approximately 1.008 g/mol.
- Oxygen (O): The molar mass of oxygen is approximately 16.00 g/mol.
Ethanol (C2H5OH) contains two carbon atoms, six hydrogen atoms (five from C2H5 and one from OH), and one oxygen atom, so we will use these values in the calculation.
Formula for Calculating Molar Mass
The molar mass of a compound is calculated using the following formula:
\[ \text{Molar Mass of Compound} = \sum (\text{Number of Atoms} \times \text{Molar Mass of Element}) \]
For ethanol (C2H5OH), the formula is:
\[ \text{Molar Mass of C}_2\text{H}_5\text{OH} = (2 \times \text{Molar Mass of C}) + (6 \times \text{Molar Mass of H}) + (1 \times \text{Molar Mass of O}) \]
Step-by-Step Calculation
Let’s now calculate the molar mass of ethanol step by step:
Step 1: Multiply the molar mass of carbon (C) by the number of carbon atoms in ethanol:
\[ 2 \times 12.01 \, \text{g/mol} = 24.02 \, \text{g/mol} \]
Step 2: Multiply the molar mass of hydrogen (H) by the number of hydrogen atoms in ethanol:
\[ 6 \times 1.008 \, \text{g/mol} = 6.048 \, \text{g/mol} \]
Step 3: Multiply the molar mass of oxygen (O) by the number of oxygen atoms in ethanol:
\[ 1 \times 16.00 \, \text{g/mol} = 16.00 \, \text{g/mol} \]
Step 4: Add the values from steps 1, 2, and 3 to find the total molar mass of ethanol:
\[ \text{Molar Mass of C}_2\text{H}_5\text{OH} = 24.02 \, \text{g/mol} + 6.048 \, \text{g/mol} + 16.00 \, \text{g/mol} \]
\[ \text{Molar Mass of C}_2\text{H}_5\text{OH} = 46.07 \, \text{g/mol} \]
Final Molar Mass of Ethanol
The molar mass of ethanol (C2H5OH) is approximately 46.07 g/mol. This means that one mole of ethanol molecules weighs 46.07 grams. Understanding the molar mass of ethanol is essential for its use in chemical reactions, fuel production, and various industrial applications where precise quantities are required.
Conclusion
The molar mass of ethanol (C2H5OH) is approximately 46.07 g/mol, calculated by summing the molar masses of two carbon atoms, six hydrogen atoms, and one oxygen atom. This value is critical in chemical processes, fermentation, fuel production, and various applications in industries that rely on ethanol as a solvent or reactant.