JEE Main levelSingle correct optionDifficulty 2 of 3pn187
Potassium chlorate (KClOX3, 122.5 g/mol) is heated with MnOX2 as catalyst: 2KClOX32KCl+3OX2. The volume of oxygen at STP (22.4 L/mol) from 12.25 g of KClOX3 is
A3.36 L
B1.12 L
C5.04 L
D2.24 L
Answer: A
Moles of KClOX3 = 12.25/122.5 = 0.10. Each mole gives 1.5 mol OX2, so 0.15 mol forms. Volume = 0.15×22.4=3.36 L.