The temperature increases due to CO2. Hence global warming is caused by CO2.
Mass cannot be created nor destroyed as well.
So, energy just goes into other things.
Example: you are born. You have carbon dioxide in your body, (or star dust). When you die, your body releases that gas.
Make sense?
I hope this helps! (:
Answer:

Explanation:
= Density of acetic acid = 
= Mass of acetic acid = 
= Volume
Density is given by

The volume of acetic acid is
.
The spoon will get warmer as it takes in the heat of the water