the answer would have to be carbon dioxide
acid
it depends upon what you want to dissolve ie if you want to dissolve a polar compound then hydrochloric acid is good but if you want to dissolve some covalent compound like benzene then water is better than HCl
The acid dissociates in water releasing H+ ions causing the compound to break up.
Sodium can dissolve. Citric acid can also dissolve into water.
No, it does not.
Calcite is the opaque compound calcium carbonate (CaCO3). It will dissolve in carbonic acid and will fizz in stronger acids. Quartz is the usually transparent compound silicon dioxide (SiO2). It will not dissolve in acid.
first dissolve in sulfuric acid and then add water
Citric acid dissolves in water in an endothermic reaction.
Chalk is calcium carbonate. Cola is an acid. When these two compounds mixed, hydrogen carbonate is formed. This compound is water soluble, and thus chalk mixed with and acid like cola dissolves in water.
yes
Yes
Dissolve cyanuric acid in a bucket full of water before adding to the pool. The hotter the water the better as the crystals take a very long time to dissolve completly in cold water.