Pressure Unit Conversion Problem

This is a worked example problem converting units of pressure.

Pressure Conversion Problem

The pressure reading from a barometer is 742 mm Hg. Express this reading in kilopascals, kPa.

Solution

This conversion may be performed using two conversion factors:

760 mm Hg = 1.013 x 10⁵ Pa

1 kPa = 10³Pa

742 mm Hg x 1.013 x 10⁵ Pa / 760 mm Hg x 1 kPa / 10³ Pa = 98.9 kPa

Answer

98.9 kPa

Always ask yourself whether your final answer seems reasonable. Atmospheric pressure is usually close to 100 kPa, so an answer of 98.9 kPa is reasonable.