Predict the order of decreasing reactivity of the following compounds towards SN1 reaction.
(A) \(\mathrm{C}_6 \mathrm{H}_5 \mathrm{CH}_2 \mathrm{Br}\)
(B) \(\mathrm{C}_6 \mathrm{H}_5 \mathrm{CH}\left(\mathrm{C}_6 \mathrm{H}_5\right) \mathrm{Br}\)
(C) \(\mathrm{C}_6 \mathrm{H}_5 \mathrm{CH}\left(\mathrm{CH}_3\right) \mathrm{Br}\)
(D) \(\mathrm{C}_6 \mathrm{H}_5 \mathrm{C}\left(\mathrm{CH}_3\right)\left(\mathrm{C}_6 \mathrm{H}_5\right) \mathrm{Br}\)

A binary ideal solution of AB type has :

In the metallurgy of Al , purified \(Al _2 O _3\) is mixed with \(Na _3 AlF _6\) or \(CaF _2\). The role of \(Na _3 AlF _6\) or \(CaF _2\) is to:

Isotonic solutions must have the same
(A) Solute
(B) Density
(C) Elevation in boiling point
(D) Depression in freezing point
Choose the correct answer from the options given below :

Acetaldehyde and benzaldehyde can be best distinguished by

A reaction takes 30 minutes to complete 50\(\%\) of the reaction and takes 45 minutes to complete 75\(\%\) of the reaction. The order of the reaction is :

Answer the question on basis of passage given below :
Lyophobic sols like those of metals (Au, Ag, etc) are unstable and are easily precipitated by addition of electrolytes. However, it is observed that the addition of certain lyophilic colloids like gums, soaps, gelatine, etc. to lyophobic colloids (like a metal sol) render lyophobic colloids difficult to coagulate by the addition of electrolytes. The process is known as 'protection' and the lyophilic colloids are termed as Protective colloids. It is believed that the protective action of the lyophilic colloids is due to the covering up of the particles of the lyophobic colloid by those of the lyophilic colloid.
Evidently, smaller the gold number of a protective colloid, the greater is its protective action.
Which of the following does not form a lyophilic colloid?

In RNA interference (RNAi) genes are silenced using :

In the Cell reaction :
\(Mg ( s )+2 Ag ^{+}( aq ) \rightarrow Mg ^{2+}( aq )+2 Ag ( s )\)
\(E _{\text {cell }}^{\circ}=3.17 V\). By doubling the concentration of \(Mg ^{2+}, E _{\text {cell }}\) is :

A swimmer's speed in still water is \(6 km / hr\). He swims between two points in a river and returns back to the starting point. He took 24 minutes more to cover the distance

Match List-I with List-II

List-I	List-II
(A) Angle between \(\hat{ \imath }-\hat{ \jmath }\) and \(\hat{ \jmath }+\hat{ k }\)	(I) 0
(B) Angle between \(2 \hat{j}-\hat{k}\) and \(\hat{j}+2 \hat{k}\)	(II) \(\frac{2 \pi}{3}\)
(C) Angle between \(\hat{i}+2 \hat{j}\) and \(5 \hat{i}+10 \hat{j}\)	(III) \(\frac{\pi}{6}\)
(D) Angle between \(\sqrt{3} \hat{i}+\hat{j}\) and \(\hat{i}\)	(IV) \(\frac{\pi}{2}\)

Choose the correct answer from the options given below:

Value of \(\int_{-4}^4|x+2| d x\) is :

Match List I with List II

LIST - I	LIST - II
A. \(\left( CH _3\right)_3 N, CH _3 CH _2 CH _2 NH _2\)	I. Tollen's test
B. \(HCOOH , CH _3 COOH\)	II. Lucas test
C. \(CH _3- C (= O )- CH _2- CH _2- CH _3, CH _3- CH _2- C (= O )- CH _2-CH _3\)	III. Carbylamine test
D. \(CH _3- CH _2- CH _2- CH _2- OH , CH _3- C \left( CH _3\right)( OH )- CH _3\)	IV. lodoform test

Choose the correct answer from the options given below