NTA Abhyas JEE Main2020Chemistryp Block Elements (Group 15, 16, 17 & 18)Practice
Pick out the incorrect statement.
Options
- AI 2 O 5 is formed by heating H I O 3 to 170 ° C
- BI 2 O 5 is stable to heat
- CI 2 O 5 is used in the estimation of CO
- DI 2 combines with O 3 to form I 4 O 9 . When heated above 75 ° C , it I 4 O 9 decomposes to form I 2 O 5
Correct answer
B. I 2 O 5 is stable to heat
Step-by-step solution
Here statement B is incorrect as I 2 O 5 is unstable to heat It decomposes when heated to 300 ° C . 2 I 2 O 5 → 300 ° C 2 I 2 + 5 O 2 Rest other statements are correct as follows (i) 2 H I O 3 → 170 ° C I 2 O 5 + H 2 O (iii) I 2 O 5 oxidizes CO to C O 2 quantitatively at room temperature, liberating I 2 , which can be titrated with sodium thiosulphate. I 2 O 5 + 5 C O → 5 C O 2 + I 2 (iv) 2 I 2 + 3 O 3 → I 4 O 9 4 I 4 O 9 → > 75 ° C 6 I 2 O 5 + 2 I 2 + 3 O 2