Question

calculate the number of atoms in 13.2 mol copper.
○ 79.5×10²³ atoms
○ 2.19×10²³ atoms
○ 7.95×10²⁴ atoms
○ 7.95×10⁻²³ atoms

Explanation:

Step1: Recall Avogadro's number

Avogadro's number is \( 6.022\times10^{23} \) atoms/mol, which represents the number of atoms (or molecules, ions, etc.) in one mole of a substance.

Step2: Use the formula to calculate number of atoms

The formula to find the number of atoms (\( N \)) is \( N = n\times N_A \), where \( n \) is the number of moles and \( N_A \) is Avogadro's number.
Given \( n = 13.2 \) mol and \( N_A = 6.022\times10^{23} \) atoms/mol.
So, \( N=13.2\space mol\times6.022\times10^{23}\space atoms/mol \)
First, calculate \( 13.2\times6.022 \):
\( 13.2\times6.022 = 13.2\times6 + 13.2\times0.022 = 79.2+0.2904 = 79.4904 \)
Then, multiply by \( 10^{23} \):
\( N = 79.4904\times10^{23}\space atoms \)
We can rewrite this in scientific notation. To do that, we know that \( 79.4904\times10^{23}=7.94904\times10^{24}\space atoms\approx7.95\times10^{24}\space atoms \)

Answer:

\( 7.95\times10^{24} \) atoms (corresponding to the option "7.95×10²⁴ atoms")