Impact : large.... ΔpKa of the order of 15 units e.g. consider H₂O (pKa = 14) vs H₃O⁺ (pKa = 0), or NH₃ (pKa = 35) vs NH₄⁺ (pKa = 10)

The charge effect is quite large, and is easier to spot (assuming the charges are assigned), best considered when the atom the H is attached to is the same.

ACIDITY : Look for factors that stabilise the conjugate base...we do this by simply removing the H+: