Answer: According to reaction below, when one mol of oxygen reacts with two mol of hydrogen, two mol of water is produced. Thus, when 2.5 mol of oxygen reacted with hydrogen, 2 * 2.5 mol = 5 mol of water is produced. The molar mass of water is 18 g/mol.
Explanation:
Not My WORK! I got this info from another site. BUT I HOPE IT HELPS :)
