Q5.12P - Chemistry: Molecular Nature Of Matter And Change

Question

If the sample flask in Figure P5.12 is open to the air, what is the atmospheric pressure (in atm)?

Step-by-Step Solution

Answer

The atmospheric pressure is 0.966 atm.

Step 1: Determination of the atmospheric pressure

The atmospheric pressure is equal to the difference in height of the mercury column.

 $∆\text{h} \text{ = } {\text{P}}_{\text{atmospheric}}$

Now, height is,

 $∆\text{h} \text{ = } 0.734 \text{m}$

Convert m into mm,

 $$\begin{gathered} 1.0 \text{m = 1000} \text{mm} \\ \Rightarrow \text{0.734} \text{m} \text{ = } \text{734} \text{mm} \end{gathered}$$

So, the atmospheric pressure is 734 mmHg.

Step 2: Conversion of unit from mmHg to atm

1 atm = 760 mmHg

Now, the pressure is,

 $\text{734} \text{mmHg} \times \frac{\text{1} \text{atm}}{\text{760} \text{mmHg}} \text{ = } \text{0.966} \text{atm}$

Thus, the atmospheric pressure is 0.966 atm.