eli5: Why is a half-dranken bottle so much colder than an unopened one when you take it out of the fridge?

Question

So I’m pretty awful at staying hydrated, so a lot of the time I end up drinking half a bottle of something and putting it back in the fridge and finishing it later (I like things cold).
I’ll put in a new bottle of Dr Pepper and hours later when I take it out, it’s decently cold. But I put it back in the fridge after drinking a bit of it. Hours later when I take it out again, it’s 5x colder. Why is that?

In: Chemistry

Answer 1

Because there’s less fluid in it. It’ll cool down faster. Same as if you used a microwave to cook 4 ounces of soup versus 8. Gonna take longer. Also, don’t hydrate with soda. It’s all caffeine and sugar. Hydrate with water. Or vodka 😂