Question

d. 7.74 x 10^26 formula units al₂o₃ to moles answer: 1.29 x 10³ mol al₂o₃

Explanation:

Step1: Recall Avogadro's number

1 mole = $6.022\times10^{23}$ formula - units

Step2: Calculate moles

$n=\frac{7.74\times 10^{26}}{6.022\times10^{23}}$ $\approx1.29\times 10^{3}$ mol

Answer:

$1.29\times 10^{3}$ mol $Al_{2}O_{3}$