What will happen to

a well stoppered bottle filled with water left in the freezer overnight?

The water would change to ice. This is because bond breaking energy is higher than bond making energy hence more heat would escape from the water. Therefore temperature would drop and water would change to ice and consequently increase in volume.

What does water do when it freezes?

It changes into ice and increases in volume?

yes, at 4C, water is at its maximum density (least volume), below that and above that it is expanding.

When a well stoppered bottle filled with water is left in the freezer overnight, a few things will likely happen:

1. Expansion of Water: As the water inside the bottle gets colder, it starts to freeze and transforms into ice. Water expands when it freezes, occupying more space than its liquid state. This expansion can put pressure on the walls of the bottle.

2. Increased Pressure: The expansion of freezing water creates an increase in pressure inside the bottle. If the bottle is well stoppered, it prevents the escape of the expanding water vapor. This accumulation of pressure can exert force on the bottle walls.

3. Bottle Integrity: If the bottle is made of a strong material, it can usually withstand the increased pressure from freezing water. However, if the bottle is not able to withstand the pressure, it may crack or even burst.

Overall, the outcome of leaving a well stoppered bottle filled with water in the freezer depends on the strength of the bottle and how well it can withstand the pressure generated by the freezing water.