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.