Elements P and Q form two types of non-volatile, non-ionizable compounds \( \mathrm{PQ} \) and \( \mathrm{PQ_2} \). When \( 1 \, \mathrm{g} \) of \( \mathrm{PQ} \) is dissolved in \( 50 \, \mathrm{g} \) of solvent ‘A’, \( \Delta T_b \) was \( 1.176 \, \mathrm{K} \) while when \( 1 \, \mathrm{g} \) of \( \mathrm{PQ_2} \) is dissolved in \( 50 \, \mathrm{g} \) of solvent ‘A’, \( \Delta T_b \) was \( 0.689 \, \mathrm{K} \). \( (K_b \) of ‘A’ \( = 5 \, \mathrm{K\,kg\,mol^{-1}} ) \). The molar masses of elements P and Q (in \( \mathrm{g\,mol^{-1}} \)) respectively, are:
