MCQ
Chlorine dioxide is best prepared by passing dry
- AChlorine gas over hot $HgO$
- BChlorine and oxygen gas over hot pt catalyst
- CHydrogen chloride and oxygen over silver oxide
- ✓Chlorine over hot silver chlorate
Reaction: $2 AgClO _3+\underset{\text { (Dry) }}{ Cl _2} \rightarrow 2 AgCl +2 ClO _2+ O _2$
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Statement $I :$ Pure Aniline and other arylamines are usually colourless.
Statement $II :$ Arylamines get coloured on storage due to atmospheric reduction.
In the light of the above statements, choose the most appropriate answer from the options given below:
| column $I$ | column $II$ |
| $(A)$ $CO _2( s ) \rightarrow CO _2( g )$ | $(p)$ phase transition |
| $(B)$ $CaCO _3( s ) \rightarrow CaO$ (s) $+ CO _2( g )$ | $(q)$ allotropic change |
| $(C)$ $2 H \bullet \rightarrow H _2( g )$ | $(r)$ $\Delta H$ is positive |
| $(D)$ $P_{\text {(white, solid) }} \rightarrow P_{\text {(red, solid) }}$ | $(s)$ $\Delta S$ is positive |
| $(t)$ $\Delta S$ is negative |
$V. P.$ of pure $B$ $p^o_B = 150\,mmHg$
A solution containing $2\,moles$ $A$ and $3\,moles$ $B$ will have total vapour pressure, approximately, on condensation ......... $mm$.