What Is The Molar Mass Of Methanol

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What Is The Molar Mass Of Methanol, CH3OH? What Is The Number Of Molecules In 1.0 Kg Of Methanol? SHOW ALL WORK

The correct answer and explanation is:

Molar Mass of Methanol (CH₃OH)

To determine the molar mass of methanol, we sum the atomic masses of all atoms in one molecule:

  • Carbon (C): 1 × 12.01 g/mol = 12.01 g/mol
  • Hydrogen (H): 4 × 1.008 g/mol = 4.032 g/mol
  • Oxygen (O): 1 × 16.00 g/mol = 16.00 g/mol

Molar mass of CH3OH=12.01+4.032+16.00=32.04 g/mol\text{Molar mass of CH}_3\text{OH} = 12.01 + 4.032 + 16.00 = 32.04 \text{ g/mol}

Number of Molecules in 1.0 kg of Methanol

  1. Convert kg to g: 1.0 kg=1000 g1.0 \text{ kg} = 1000 \text{ g}
  2. Find the number of moles (n): n=MassMolar Massn = \frac{\text{Mass}}{\text{Molar Mass}} n=1000 g32.04 g/mol=31.22 molesn = \frac{1000 \text{ g}}{32.04 \text{ g/mol}} = 31.22 \text{ moles}
  3. Find the number of molecules using Avogadro’s number:
    • Avogadro’s number: 6.022×10236.022 \times 10^{23} molecules/mol
    Number of molecules=n×Avogadro’s number\text{Number of molecules} = n \times \text{Avogadro’s number} =31.22 moles×6.022×1023 molecules/mol= 31.22 \text{ moles} \times 6.022 \times 10^{23} \text{ molecules/mol} =1.88×1025 molecules= 1.88 \times 10^{25} \text{ molecules}

Final Answers:

  • Molar mass of methanol (CH₃OH): 32.04 g/mol
  • Number of molecules in 1.0 kg of methanol: 1.88×10251.88 \times 10^{25} molecules

Explanation

Methanol (CH₃OH) is an organic compound with one carbon atom, four hydrogen atoms, and one oxygen atom. To determine the molar mass, we sum up the atomic masses of its elements. Carbon has an atomic mass of 12.01 g/mol, hydrogen is 1.008 g/mol (four atoms total), and oxygen is 16.00 g/mol. Adding these together gives the molar mass of 32.04 g/mol.

Next, to find how many molecules are in 1.0 kg (1000 g) of methanol, we first calculate the number of moles. The formula for moles is mass divided by molar mass. By dividing 1000 g by 32.04 g/mol, we get 31.22 moles.

Since each mole contains Avogadro’s number of molecules (6.022×10236.022 \times 10^{23}), we multiply the number of moles by Avogadro’s number. This results in 1.88×10251.88 \times 10^{25} molecules.

This calculation is important in chemistry, as it helps scientists determine the quantity of substances at a molecular level. Molar mass is fundamental in stoichiometry, which is used in reactions to predict yields and reactant amounts. Understanding Avogadro’s number allows conversion between macroscopic masses and microscopic particles.

In real-world applications, methanol is used as fuel, an industrial solvent, and an antifreeze. Understanding its molar mass helps industries calculate the required amounts for production processes.

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