You can certainly put a water bottle in the freezer. Freezing a water bottle is a common method to keep water cold for longer periods, especially when you want to have it chilled for outdoor activities, trips, or for general convenience.
When placing a water bottle in the freezer, it's essential to leave some headspace in the bottle for the water to expand as it freezes. If the bottle is completely filled, the expanding ice may cause the bottle to crack or burst. It's generally recommended to leave about 10-20% of empty space in the bottle to allow for expansion.
Keep in mind that freezing water causes it to expand, which can lead to changes in the texture and taste of the water. Additionally, if the water bottle is made of glass, it's important to handle it with caution to avoid breakage when frozen.
On the other hand, if you prefer your water to be chilled but not frozen, you can place the water bottle in the refrigerator instead. The fridge will cool the water to a lower temperature without freezing it completely.