Multiple Choice
How many formula units are in 8.38 g of LiOH?
2. Atoms & Elements
Mole Concept
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How many molecules of CH4 are present in 43.2 grams of methane (CH4)?
A
3.00 x 10^22 molecules
B
1.50 x 10^23 molecules
C
6.02 x 10^23 molecules
D
2.60 x 10^24 molecules
Verified step by step guidance1
First, determine the molar mass of methane (CH4). Methane consists of one carbon atom and four hydrogen atoms. The atomic mass of carbon is approximately 12.01 g/mol, and the atomic mass of hydrogen is approximately 1.01 g/mol. Calculate the molar mass of CH4 using the formula: \( \text{Molar mass of CH}_4 = 12.01 + 4 \times 1.01 \).
Next, convert the given mass of methane (43.2 grams) into moles. Use the formula: \( \text{moles of CH}_4 = \frac{\text{mass of CH}_4}{\text{molar mass of CH}_4} \). Substitute the values you have to find the number of moles.
Now, use Avogadro's number to convert moles of CH4 to molecules. Avogadro's number is \( 6.022 \times 10^{23} \) molecules/mol. Multiply the number of moles of CH4 by Avogadro's number to find the number of molecules: \( \text{molecules of CH}_4 = \text{moles of CH}_4 \times 6.022 \times 10^{23} \).
Compare the calculated number of molecules with the options provided in the problem to identify the correct answer.
Finally, verify your calculations to ensure accuracy and confirm that the correct answer is \( 2.60 \times 10^{24} \) molecules.
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