What is the independent variable for this experiment?

What is the number of moles of chemical units represented by 9.03x10^24? and how do i show work? (dumb it down )

Phosphorous acid, h3po3(aq) , is a diprotic oxyacid that is an important compound in industry and agriculture. p k a1 p k a2 1.30 6.70 calculate the ph for each of the points in the titration of 50.0 ml of 1.5 m h3po3(aq) 1.5 m h 3 po 3 ( aq ) with 1.5 m koh(aq). 1.5 m koh ( aq ) .

Δu of , in kj/kg, as it isto k, (a)as a of , (b) at , (c) at .