# What is the equivalent pressure of 0.743 atm in units of mm Hg?

##### 1 Answer

#### Explanation:

The problem wants you to use a known *conversion factor* to go from pressure expressed in **atmospheres**, **millimeter of mercury**,

Now, you can find the conversion factor that takes you from atmospheres to millimeter of mercury by using the **pascals**,

In terms of pascals, an atmosphere is defined as a pressure of

#"1 atm " = " 101325 Pa"#

Similarly, a millimeter of mercury, which is simply the pressure exerted by a

#"1 mmHg " ~~ " 133.32239 Pa"# .

Your goal now is to find *how many* milliliters of mercury are needed to get to the equivalent of one atmosphere. You can say that you have

#overbrace(101325 color(red)(cancel(color(black)("Pa"))))^(color(blue)("= 1 atm")) * "1 mmHg"/(133.32239color(red)(cancel(color(black)("Pa")))) ~~ "760 mmHg"#

This tells you that a column of mercury **high** creates a pressure equal to

You can thus say that your conversion factor looks like this

#color(purple)(|bar(ul(color(white)(a/a)color(black)("1 atm " = " 760 mmHg")color(white)(a/a)|)))#

Use this conversion factor to find the equivalent pressure of

#0.743 color(red)(cancel(color(black)("atm"))) * "760 mmHg"/(1color(red)(cancel(color(black)("atm")))) = color(green)(|bar(ul(color(white)(a/a)color(black)("565 mmHg")color(white)(a/a)|)))#

The answer is rounded to three **sig figs**.