During electrolysis of acidified water, 2.8 Litre of oxygen gas is released (at STP). The charge passed through the anode is -

Aryl halides are extremely less reactive towards nucleophilic substitution reaction because of

Reaction of \(C _6 H _5 CH _2 Br\) with aqueous sodium hydroxide follows

The increasing order of the melting points of following transition metals is
(A) Fe
(B) Mn
(C) Cr
(D) V
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The correct increasing order of reactivity of alkyl halides with \(CH _3 NH _2\) is
(A) \(C _2 H _5- Br\)
(B) \(C _2 H _5- I\)
(C) \(C _2 H _5- F\)
(D) \(C _2 H _5- Cl\)
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The ore which cannot be concentrated by froth-flotation process is:

Give the reason for low concentration of oxygen in the blood and tissues of people living at high altitude

During lockdown, Amit was suffering from heart problem. After proper check-up it was deducted that he has \(45\%\) chance of having heart attack, but yoga and meditation assumed to reduce the chance of heart attack by \(25\%\) and \(20\%\) respectively. He has option to choose any of the two options with equal probabilities.
If Amit goes through one of the two options selected at random and suffers a heart attack, then the probability that he had selected yoga is:

Which type of isomerism is shown by the complex compounds?
\(\left[ Co \left( NH _3\right)_5 Br \right] SO _4\) and \(\left[ Co \left( NH _3\right)_3 SO _4\right]\)Br

Read the passage carefully and answer the questions
Amines are considered as derivatives of ammonia obtained by replacement of hydrogen atoms with alkyl or aryl groups. In nature they occur among proteins, vitamins, alkaloids and hormones. These can be primary, secondary or tertiary depending on the number of hydrogen groups replaced. They can be prepared from nitro compounds, alkyl halides, nitriles, amides etc. Due to unshared pair of electrons they behave as Lewis bases. Influence of the number of hydrogen atoms at nitrogen atom is displayed in physical properties such as solubility, boiling point and chemical reactions including basicity. Basic character of amines is expressed in terms of their \(K_b\) and \(p K_b\) values. Three classes of amines can be distinguished with p-toluene sulphonyl chloride which reacts with primary and secondary ddu amines. Amino group when attached to benzene ring behaves as an activating and ortho para directing group.
Which of the following reaction is not given by aniline?

The points on the ellipse \(\frac{x^2}{9}+\frac{y^2}{25}=1\) at which the tangents are parallel to the \(x\)-axis are:

Displacement current exists only when

Which of the following statements are true about phosphorous cycle?
A. There is no respiratory release of phosphorus in the atmosphere
B. The reservoir of phosphorus is rock
C. There are large atmospheric inputs of phosphorus through rainfall
D. The gaseous exchange of phosphorus between organisms and environment is negligible
Choose the correct answer from the options given below: