For AB ‌∆Tb=2.7 ‌Kb=0.5K‌kg‌mol−1 ‌m=‌
∆Tb
Kb
=5.4m For AB2 ‌∆Tb=1.5K ‌m=‌
1.5
0.5
=5.4m Moles of AB =0.081‌mol
Moles of AB2 =0.045‌mol Molar mass of AB=12.35g∕mol Molar mass of AB2=22.22g∕mol Let atomic mass of A=a,B=b a+b=12.35 a+2b=22.22 On solving a=2.48 =24.8×10−1