Question

What is the pressure (in Pa) of the gas in the flask in Figure P5.13?

Short answer

The pressure of the gas is $\text{4.75×10}{ }^{\text{3}} \text{Pa}$.

Step-by-step solution

Determination of the pressure 

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

$∆\text{h} {\text{=P}}_{\text{gas}}$

Now, the difference in height of the mercury column is :

$∆\text{h} \text{=} \text{3.56} \text{cm}$

Convert m into mm,

$$\begin{gathered} \text{1} \text{cmHg} \text{=} \text{10} \text{mmHg} \\ \Rightarrow 3.56 cmHg = 35.6 mmHg \end{gathered}$$

So, the pressure is 35.6 mmHg.

Conversion of unit from mmHg to Pascal (Pa) 

1 mmHg = 133.322 Pa

Now, the pressure is,

$35.6 \text{mmHg} \times \frac{133.322 \text{Pa}}{1 \text{mmHg}} = 4.75\times {10}^3 \text{Pa}$

Thus, the pressure of the gas is $\text{4.75} \times \text{10}{ }^{\text{3}} \text{Pa}$.