# If a gas pressure gauge reads 15 mm Hg, what is the pressure in atmospheres?

Jun 12, 2017

0,020 atmospheres

#### Explanation:

760 mm Hg = 1 atmosphere.

$\frac{15}{760} = a t m o s p h e r e$

 15/760 = 0.0197368 atmospheres rounding off to 2 significant digits gives

0.020 atmospheres

Jun 12, 2017

$0.020$ $\text{atm}$

#### Explanation:

To convert between millimeters Mercury ($\text{mm Hg}$) and atmospheres ($\text{atm}$), we use the conversion factor

$\left(1 \text{atm")/(760"mm Hg}\right)$

That is, $1$ atmosphere equals $760$ millimeters Mercury.

Using dimensional analysis, we can convert the given pressure:

$15$ cancel("mm Hg")((1"atm")/(760cancel("mm Hg"))) = color(red)(0.020 color(red)("atm"

$15$ $\text{mm Hg}$ is equal to $0.020$ $\text{atm}$, rounded to color(blue)(2# significant figures, the amount given in the problem.