College

If a gas has a gauge pressure of 156 kPa, its absolute pressure is approximately:

A. 100 kPa
B. 300 kPa
C. 256 kPa
D. 56 kPa

Answer :

To find the absolute pressure of a gas when given the gauge pressure, we need to understand the relationship between gauge pressure and absolute pressure.

The gauge pressure is the pressure of a gas relative to the atmospheric pressure. Absolute pressure, on the other hand, is the total pressure exerted by a gas, including the atmospheric pressure.

Here’s the formula to convert gauge pressure to absolute pressure:

[tex]\[ \text{Absolute Pressure} = \text{Gauge Pressure} + \text{Atmospheric Pressure} \][/tex]

In this problem, the given gauge pressure is 156 kPa. The approximate value for standard atmospheric pressure is typically taken as 100 kPa.

Now, let's calculate the absolute pressure:

1. Add the gauge pressure to the atmospheric pressure:
[tex]\[ 156 \, \text{kPa} + 100 \, \text{kPa} = 256 \, \text{kPa} \][/tex]

So, the absolute pressure is approximately 256 kPa.

Therefore, the best answer is:
- Option C: 256 kPa