A mixture of 1.65 × 1021 molecules of X and1.85 x 1021 molecules of Y weighs 0.688 g. Themol. wt. of X is (Assume mol. wt, of Y is 187).
A molecule A2B (mol. wt. = 166.4) occupies triclinic lattice witha=5A∘,b=8A∘andC=4A∘.If density of AB2is 5.2 g cm-3, the number of molecules present in one unit cell is :