How much does 1 gallon of water weigh

General
1

how much does 1 gallon of water weigh

2

How much does 1 gallon of water weigh?

Answer:
To determine the weight of 1 gallon of water, it’s essential to understand the properties of water and the units involved. Here’s a detailed explanation:

1. Definition of a Gallon

A gallon is a unit of volume measurement used primarily in the United States but also recognized in other countries under different forms:

  • US Liquid Gallon: Commonly used in the United States, which is equal to 3.78541 liters.
  • Imperial Gallon: Used in the United Kingdom, Canada, and some Caribbean nations, which equals 4.54609 liters.

2. Weight of Water at Standard Temperature

Water has different weights under different temperatures and pressures. Standard weight calculations are typically carried out at the temperature where water is most dense, approximately 4°C (39.2°F).

For simplicity, let’s consider the weight of water at ordinary room temperature, around 20°C (68°F).

3. Conversion and Calculation

The weight of a substance is related to its volume and density. The density of water at 20°C is approximately 0.9982 grams per cubic centimeter (g/cm³).

A. US Liquid Gallon

1 US gallon = 3.78541 liters
1 liter = 1000 cubic centimeters (cm³)

So,

3.78541 \text{ liters} \times 1000 \frac{\text{cm}³}{\text{liter}} = 3785.41 \text{ cm}³

Given that 1 cubic centimeter of water weighs approximately 0.9982 grams:

3785.41 \text{ cm}³ \times 0.9982 \frac{\text{grams}}{\text{cm}³} \approx 3778.77 \text{ grams}

To convert grams to pounds:
1 pound ≈ 453.592 grams

3778.77 \text{ grams} \div 453.592 \approx 8.345 \text{ pounds}

B. Imperial Gallon

1 Imperial gallon = 4.54609 liters

So,

4.54609 \text{ liters} \times 1000 \frac{\text{cm}³}{\text{liter}} = 4546.09 \text{ cm}³

Given that 1 cubic centimeter of water weighs approximately 0.9982 grams:

4546.09 \text{ cm}³ \times 0.9982 \frac{\text{grams}}{\text{cm}³} \approx 4542.54 \text{ grams}

To convert grams to pounds:

4542.54 \text{ grams} \div 453.592 \approx 10.022 \text{ pounds}

Final Answer:

  • US Liquid Gallon of water weighs approximately 8.345 pounds (3.785 kilograms).
  • Imperial Gallon of water weighs approximately 10.022 pounds (4.546 kilograms).

These weights are approximate and can vary slightly with changes in temperature and atmospheric pressure.