Q5 / 160 · TS EAMCET 2006 · Chemistry
Which of the following is not correct?
- Correct answerA$3 \mathrm{O}_2 \underset{\text { discharge }}{\stackrel{\text { silent electric }}{\rightleftarrows}} 2 \mathrm{O}_3 ; \Delta H=-284.5 \mathrm{~kJ}$
- BOzone undergoes addition reaction with unsaturated carbon compounds
- CSodium thiosulphate reacts with $\mathrm{I}_2$ to form sodium tetrathionate and sodium iodide.
- DOzone oxidises lead sulphide to lead sulphate.
Solution
The formation of ozone from oxygen is an endothermic reaction not exothermic reaction.
$3 \mathrm{O}_2 \underset{\text { discharge }}{\stackrel{\text { Electric }}{\longrightarrow}} 2 \mathrm{O}_3 \quad \Delta H=287 \mathrm{~kJ}$
So, statement
$3 \mathrm{O}_2 \underset{\text { discharge }}{\stackrel{\text { silent }}{\rightleftharpoons}} 2 \mathrm{O}_3 \quad \Delta H=-284.5 \mathrm{~kJ}$
is not correct statement.
Hence, the correct answer is option: 'A'.