Why is a one-gallon container of water heavier than a one-gallon container of whole milk? A) Water has more mass than milk. B) Milk has more mass than water. C) The containers have different weights. D) The question is based on incorrect information.
The Correct Answer and Explanation is:
The correct answer is D) The question is based on incorrect information.
In reality, a one-gallon container of whole milk is heavier than a one-gallon container of water, not the other way around. This is because of the differences in density between water and milk. Density is defined as mass per unit volume, and it determines how much mass is contained in a specific volume of a substance.
Explanation:
- Water’s density is approximately 1 gram per milliliter (g/mL), which means that 1 liter (1000 mL) of water has a mass of about 1 kilogram. Since 1 gallon is equivalent to approximately 3.785 liters, the mass of a gallon of water is around 3.785 kilograms (or about 8.34 pounds).
- Milk, especially whole milk, is a mixture of water, fat, proteins, and sugars like lactose. These additional components increase the density of milk compared to water. The density of whole milk is typically around 1.03 g/mL, slightly higher than water. As a result, a gallon of whole milk weighs more than a gallon of water. For example, a gallon of whole milk weighs around 8.6 pounds (or approximately 3.9 kilograms), which is heavier than the same volume of water.
The idea that a gallon of water is heavier than a gallon of milk is a misunderstanding. It is important to consider that while both water and milk are mostly composed of water (about 87% of milk is water), the extra components in milk (fats and proteins) increase its overall mass.
This is why, in the context of the question, the statement is inaccurate and the best answer is that the question is based on incorrect information. Therefore, when comparing one gallon of water and one gallon of whole milk, the milk is the heavier substance.