Answer :
Final answer:
If a gas has a gauge pressure of 156 kPa, the absolute pressure is the sum of this gauge pressure and the atmospheric pressure, which gives approximately 257.3 kPa. Thus, the correct answer is 256 kPa.
Explanation:
When considering the pressure of a gas, there are two key types to understand: gauge pressure and absolute pressure. Gauge pressure is the pressure of the gas above atmospheric pressure. Atmospheric pressure at sea level is approximately 101.3 kPa (101,325 Pa). So, when we have a gauge pressure reading, we must add the atmospheric pressure to it to get the absolute pressure. In this case, if a gas has a gauge pressure of 156 kPa, to find the absolute pressure, we add the atmospheric pressure (approximately 101.3 kPa) to it, which gives us a total of 257.3 kPa. Therefore, the correct answer is a. 256 kPa, since this is the closest approximate value.
