By what factor does [h + ] change for each ph change? (a) 3.20 units

When a change in PH = 10^-ΔPH

so the change = 10^-3.2

change depends on two factor 0.00063 (10^-3.2) and factor 1585 (10^3.2) depending on the way which the change goes. if PH change from PH=0 to PH = 3.2 so the change is decreasing from concentration from 1 mol to 0.00063 and if PH change from PH = 3.2 to PH=0 so the change is increasing by a factor of 1585.