What happens to the weight of a gallon of water if impurities are added?

When impurities are added to a gallon of water, the total weight of the solution increases. This is because the added impurities contribute additional mass to the mixture. For instance, if salt, sugar, or any other substance is dissolved in the water, the overall volume will still be approximately a gallon, but the mass will be greater since those impurities have weight.

The principle here is that the weight of any solution is the sum of the weights of the individual components. Since water has a specific weight per gallon, and the impurities also have their own weight, the combination results in an increase in total weight. This understanding is fundamental in various applications, such as when calculating chemical mixtures or when dealing with environmental impacts in agriculture.