How much does one gallon of water weigh in pounds?

One gallon of water weighs approximately 8.34 pounds at standard temperature and pressure. This value is widely used in various calculations in engineering, environmental science, and other fields because it reflects the density of water at its most common state.

When determining the weight of water, knowing that 8.34 pounds per gallon is the accepted standard helps in designing systems that involve fluid dynamics, such as pipelines, water treatment plants, and other mechanical systems.

The other options do not accurately represent the weight of a gallon of water under typical conditions. For example, 7.48 pounds is the weight of a US gallon of liquid (not specifically water) as it pertains to different fluids and their unique densities. The options of 9.0 pounds and 10.0 pounds are incorrect as they overestimate the weight of a gallon of water, which could lead to errors in calculations related to fluid weight and pressure.