Question

1. how many hydrogen atoms are there in 7.30 moles of ethanol (c₂h₅oh)?

options:
1.21 × 10⁻²³ atoms
2.64 × 10²⁵ atoms
4.39 × 10²⁴ atoms
2.20 × 10²⁵ atoms

Explanation:

Step1: Determine H atoms in ethanol

Ethanol formula: $\ce{C2H5OH}$. Count H atoms: 5 (from $\ce{C2H5}$) + 1 (from $\ce{-OH}$) = 6 H atoms per molecule.

Step2: Use Avogadro's number

Avogadro's number: $N_A = 6.022 \times 10^{23}$ atoms/mol. Moles of ethanol: $n = 7.30$ mol.

Step3: Calculate total H atoms

First, moles of H: $n_{\ce{H}} = 7.30 \, \text{mol} \times 6 = 43.8 \, \text{mol}$.
Then, number of H atoms: $N = n_{\ce{H}} \times N_A = 43.8 \, \text{mol} \times 6.022 \times 10^{23} \, \text{atoms/mol}$.
Calculate: $43.8 \times 6.022 \times 10^{23} \approx 263.7636 \times 10^{23} = 2.637636 \times 10^{25} \approx 2.64 \times 10^{25}$ atoms.

Answer:

2.64 × 10²⁵ atoms (corresponding to the option "2.64 × 10²⁵ atoms")