Statement (I) : pKa of NH3 > pKa of PH3Statement (II) : N-H bond is less polar than P-H bond

Acidic strength in Hydrides of any group is explained on the basis of X-H bond enthalpy but not on the basis of X-H bond polarity.EN of H(2.1) ;  EN of N(3.0) ; EN of P(2.5)N - H bond is more polar than P-H bondN - H bond enthalpy is more than P - H bond enthalpy∴ NH3 is a weaker acid (lesser Ka & higher pKa   as compared to PH3)