Question

According to the mole concept in chemistry, what is the number of carbon atoms in 12 g of Carbon-12?

• A. \(6.022 \times 10^{23}\)
• B. \(6.022 \times 10^{-23}\)
• C. \(1.602 \times 10^{19}\)
• D. \(1.602 \times 10^{-19}\)

Hint:

Always remember: \[ 12 \text{ g Carbon-12} = 1 \text{ mole} \] and \[ 1 \text{ mole} = 6.022 \times 10^{23} \] particles, atoms, molecules, or ions.

Answer 1

The Correct Option is A

Concept: The mole concept is one of the most fundamental concepts in chemistry. A mole is defined as the amount of a substance that contains exactly the same number of elementary entities as there are atoms in \(12\) g of Carbon-12. This fixed number is known as Avogadro's Number and is represented by: \[ N_A = 6.022 \times 10^{23} \] The significance of this definition is that \(12\) g of Carbon-12 contains exactly one mole of carbon atoms.

Step 1: Recall the definition of one mole
By definition, \[ 1 \text{ mole of Carbon-12} \] contains \[ 6.022 \times 10^{23} \] carbon atoms. Also, \[ 1 \text{ mole of Carbon-12} = 12 \text{ g} \] Therefore, \[ 12 \text{ g of Carbon-12} \] represents exactly one mole.

Step 2: Determine the number of atoms present
Since \(12\) g corresponds to one mole, the number of carbon atoms present will be equal to Avogadro's number. Hence, \[ \text{Number of atoms} = 6.022 \times 10^{23} \]

Step 3: Verify the options
Option (A): \[ 6.022 \times 10^{23} \] matches Avogadro's number exactly. Option (B): \[ 6.022 \times 10^{-23} \] has an incorrect negative exponent. Option (C): \[ 1.602 \times 10^{19} \] represents neither Avogadro's number nor the number of atoms in one mole. Option (D): \[ 1.602 \times 10^{-19} \] is approximately the magnitude of electronic charge and is unrelated to this question. Final Conclusion: The number of carbon atoms present in \(12\) g of Carbon-12 is \[ \boxed{6.022 \times 10^{23}} \] Therefore, the correct option is \[ \boxed{(A)} \]