# The vapor pressure of solid iodine at 25 °C is 42 mmHg. What is the vapor pressure in atm and torr?

Jun 10, 2017

$0.055$ $\text{atm}$

$42$ $\text{torr}$

#### Explanation:

We're asked to convert a given pressure value to two other units: $\text{atm}$ and $\text{torr}$.

Here's a simple conversion factor:

$1$ $\text{mm Hg} = 1$ $\text{torr}$

Therefore, $42$ "mm Hg" = color(red)(42 color(red)("torr"

The conversion factor for $\text{mm Hg}$ and $\text{atm}$ is

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

Therefore, using dimensional analysis,

$42$ cancel("mm Hg")((1"atm")/(760cancel("mm Hg"))) = color(red)(0.055 color(red)("atm"

rounded to color(blue)(2 significant figures, the amount given in the problem.