Q. The Aryans dedicated whole of a separate Mandala in Rig-Veda for the hymns dedicated to __? Answer:
Soma
Notes: The IX Mandala of the Rigveda also known a Soma Mandala is dedicated to Soma Pavamana (purifying Soma) i.e. the sacred potion Somaras. It is made from the plant of the same name. Basically the Rigveda refers to the drink, the plant and the God with the same name Soma. It was believed to be the drink of Gods.