What happens to the mass of a beaker of water with a teaspoon of sugar in it measured on a balance pan compared to a teaspoon of sugar and a beaker of water separated on a balance pan? does the mass increase, decrease or stay the same? and why?

An example:

1. beaker with mass 50.0 g + sugar with mass 10.0 grams + water with 25.0 = total 85.0 g

2. beaker 50.0 g
sugar 10.0 g
water 25.0 g.
Total = 85.0 grams.
Since the sugar only dissolves (a physical change, not a chemical change) and there is no reaction, there is no loss or gain of mass so it matters little if the water and sugar are mixed.

To determine what happens to the mass of a beaker of water with a teaspoon of sugar in it compared to a teaspoon of sugar and a beaker of water separated, let's break it down step by step.

1. Beaker of water with a teaspoon of sugar:
When you add a teaspoon of sugar to a beaker of water and measure it on a balance pan, the total mass will increase. The reason is that both the sugar and the water have their own individual masses. When combined, their masses become additive, resulting in an increased total mass.

2. Teaspoon of sugar and a beaker of water separated:
If you measure a teaspoon of sugar and a beaker of water separately on a balance pan, the total mass will stay the same. When you measure each component independently, the mass of the sugar and the mass of the water are measured separately and not combined. Therefore, the total mass remains unchanged.

In summary:
- When the sugar is added to the water, the total mass increases because the individual masses of sugar and water are combined.
- When the sugar and water are measured separately, the total mass remains the same as the individual masses are measured independently.

It's important to note that the mass of an object is conserved in a closed system, meaning it does not appear or disappear. It can only be redistributed or combined with other objects.