Question

The number of atoms in 0.1 mole of a triatomic gas will be (NA = \( 6.02 \times 10^{23} \)):

• A. \( 1.800 \times 10^{22} \)
• B. \( 6.026 \times 10^{22} \)
• C. \( 1.806 \times 10^{23} \)
• D. \( 3.600 \times 10^{23} \)

Hint:

To find the total number of atoms, multiply: \[ \text{Moles of gas} \times N_A \times \text{Atoms per molecule} \] For triatomic gases, multiply by 3.

Answer 1

The Correct Option is C

We are given:

• Number of moles of gas \( = 0.1 \)
• Nature of gas: Triatomic \( \Rightarrow \) Each molecule contains 3 atoms
• Avogadro's number \( N_A = 6.02 \times 10^{23} \) molecules per mole

Step-by-step calculation: \[ \text{Number of molecules} = 0.1 \times 6.02 \times 10^{23} = 6.02 \times 10^{22} \] Since each molecule has 3 atoms (because it’s triatomic), the total number of atoms will be: \[ \text{Number of atoms} = 6.02 \times 10^{22} \times 3 = 18.06 \times 10^{22} = 1.806 \times 10^{23} \] This value is not among the given options, but we must recheck carefully. Wait! The correct multiplication is: \[ 0.1 \text{ mole} \times 6.02 \times 10^{23} \text{ molecules/mole} = 6.02 \times 10^{22} \text{ molecules} \] Each molecule has 3 atoms: \[ 6.02 \times 10^{22} \times 3 = 18.06 \times 10^{22} = \boxed{1.806 \times 10^{23}} \] So, the correct option is: \[ \boxed{\text{(3) } 1.806 \times 10^{23}} \]