# Question fa66b

Apr 7, 2017

$1.76 \cdot {10}^{25}$

#### Explanation:

For starters, you know that $1$ mole of boron trifluoride contains

• one mole of boron, $1 \times \text{B}$
• three moles of fluorine, $3 \times \text{F}$

This implies that your sample of boron trifluoride will contain

9.72 color(red)(cancel(color(black)("moles BF"_3))) * "3 moles F"/(1color(red)(cancel(color(black)("mole BF"_3)))) = "29.16 moles F"#

Now, $1$ mole of any element contains $6.022 \cdot {10}^{23}$ atoms of that element $\to$ this is known as Avogadro's constant.

You can thus say that your sample will contain

$29.16 \textcolor{red}{\cancel{\textcolor{b l a c k}{\text{moles F"))) * (6.022 * 10^(23)color(white)(.)"atoms of F")/(1color(red)(cancel(color(black)("mole F")))) = color(darkgreen)(ul(color(black)(1.76 * 10^(25)color(white)(.)"atomf of F}}}}$

The answer is rounded to three sig figs, the number of sig figs you have for the number of moles of boron trifluoride.