How many moles of butane, C4H10, are found in 392.3 grams of C4H10?
The correct answer and explanation is:
To determine how many moles of butane (C₄H₁₀) are in 392.3 grams, we need to use the concept of molar mass. The molar mass of butane is calculated by adding up the atomic masses of all the atoms in one molecule of C₄H₁₀.
Step 1: Calculate the molar mass of C₄H₁₀.
- Carbon (C) has an atomic mass of approximately 12.01 g/mol.
- Hydrogen (H) has an atomic mass of approximately 1.008 g/mol.
For C₄H₁₀: - 4 carbon atoms contribute 4 × 12.01 = 48.04 g/mol.
- 10 hydrogen atoms contribute 10 × 1.008 = 10.08 g/mol.
So, the molar mass of butane is:
48.04 + 10.08 = 58.12 g/mol.
Step 2: Use the formula to calculate the number of moles.
The number of moles (n) is given by the formula: n=mass (g)molar mass (g/mol)n = \frac{\text{mass (g)}}{\text{molar mass (g/mol)}}
Substitute the given values: n=392.3 g58.12 g/moln = \frac{392.3 \, \text{g}}{58.12 \, \text{g/mol}} n≈6.74 molesn ≈ 6.74 \, \text{moles}
So, the number of moles of butane in 392.3 grams is approximately 6.74 moles.
Explanation:
Moles are used to count the number of particles (atoms, molecules, or ions) in a substance. The molar mass gives the mass of one mole of a substance. By dividing the mass of the substance by its molar mass, we can calculate how many moles of that substance are present. In this case, by finding the molar mass of butane and dividing the given mass by it, we can determine how many moles of butane are in 392.3 grams.