How many molecules are present in 4 moles of NH_3?

• A. 2.41 \times 10^{24} molecules
• B. 2.41 \times 10^{24} molecules
• C. 2.41 \times 10^{24} atoms
• D. 4.00 \times 10^{23} molecules

Answer: (B)

Verified step by step guidance

1. Identify the quantity given: 4 moles of NH_3 (ammonia).
2. Recall Avogadro's number, which is the number of molecules in one mole of any substance: \$6.022 \times 10^{23}$ molecules/mole.
3. Set up the calculation to find the total number of molecules by multiplying the number of moles by Avogadro's number: \(\text{Number of molecules} = 4 \text{ moles} \times 6.022 \times 10^{23} \text{ molecules/mole}\).
4. Perform the multiplication (conceptually) to find the total molecules present in 4 moles of NH_3.
5. Express the answer in scientific notation to match the format of the options given.