JEE Advanced levelSingle correct optionDifficulty 3 of 3mc147
A compound contains 40% C, 6.67% H and 53.33% O by mass. 0.90 g of its vapour occupies 224 mL at STP (22.4 L/mol). Its molecular formula is (C=12, H=1, O=16)
ACX3HX6OX3
BCHX2O
CCX2HX4OX2
DCX6HX12OX6
Answer: A
Mole ratio C:H:O = 40/12 : 6.67/1 : 53.33/16 = 3.33 : 6.67 : 3.33 = 1:2:1, empirical formula CHX2O (30). Molar mass = 0.90/(0.224/22.4) = 90. n = 90/30 = 3, so CX3HX6OX3.