At sea level, the standard atmospheric pressure expressed in psi can be approximated as which value?

At sea level, the standard atmospheric pressure expressed in psi can be approximated as which value?

• A. 9.8 psi
• B. 5.2 psi
• C. 21.0 psi
• D. 14.7 psi

Answer: (D)

At sea level the pressure exerted by the atmosphere is defined as one atmosphere, which equals about 14.7 pounds per square inch. This standard atmospheric pressure comes from 101.3 kilopascals, and when converted to psi it is approximately 14.696 psi, often rounded to 14.7 psi. This baseline is important in hazmat work for understanding how gases behave, comparing ambient pressure to container or vapor pressures, and sizing relief devices. The other numbers don’t match the true ambient air pressure: 9.8 psi is lower than the actual atmospheric pressure and is not a pressure reference for air; 5.2 psi is also not the standard atmospheric value; 21.0 psi is higher, around 1.43 atm, not sea level standard. So the correct approximation is 14.7 psi.

At sea level the pressure exerted by the atmosphere is defined as one atmosphere, which equals about 14.7 pounds per square inch. This standard atmospheric pressure comes from 101.3 kilopascals, and when converted to psi it is approximately 14.696 psi, often rounded to 14.7 psi. This baseline is important in hazmat work for understanding how gases behave, comparing ambient pressure to container or vapor pressures, and sizing relief devices. The other numbers don’t match the true ambient air pressure: 9.8 psi is lower than the actual atmospheric pressure and is not a pressure reference for air; 5.2 psi is also not the standard atmospheric value; 21.0 psi is higher, around 1.43 atm, not sea level standard. So the correct approximation is 14.7 psi.