Statement (I): Both $H_{3}P{O}_3$ and $H_{3}P{O}_4$ have same number of hydrogen atoms but $H_{3}P{O}_4$ is a tribasic acid and $H_{3}P{O}_3$ is a dibasic acid 
Statement (II): 1 mole of $H_{3}P{O}_3$ is neutralized by 2 moles of NaOH, while 1 mole of $H_{3}P{O}_4$ is neutralized by 3 moles of NaOH