The hydrosphere is composed of water, which is made up of hydrogen and oxygen, in the formula H20. P.E
The chemical component of hydrosphere (water) is Oxygen and Hydrogen.
2H + O = H2O (water). The other chemical compound is Salt water which a mixture of Sodium and Water. NaCl(aq) (salt water). R.D

There are other chemical compounds present in sea water such as NaCl, Carbon, Sulfur etc.
Seawater composition.png
This is from Wikipedia. B.H