# The mass of a beaker containing a sample of water at 20°C was 109.44 g. After heating the sample to 60°C, the combined mass of the beaker and water was 109.08 g. Do these results contradict the law of conservation of mass?

Sep 27, 2017

#### Answer:

They would if it were a closed system....

#### Explanation:

So how do we account for the mass loss? Clearly, evaporation has occurred and water, as vapour, has been lost from the beaker. How much water has been lost?

Had we heated to $90$ ""^@C would you expect mass loss to be more or less than the given scenario?