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?

Answer 1

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.