NSES Content Standard D   Earth and Space Science: Structure of the Earth system  Grades 5-8, page 160  Water is a solvent. As it passes through the water cycle it dissolves minerals and gases and carries them to the oceans.

 
Benchmark 4D The Physical Setting: Structure of Matter
Grades 6-8, page 78
The temperature and acidity of a solution influence reaction rates. Many substances dissolve in water, which may greatly facilitate reactions between them.