The carboxylic acid that does not undergo Hell-Volhard-Zelinsky reaction is:

How many \(Cr-O\) bonds in dichromate ions are of the same bond length and are in resonance?

Answer the question on the basis of passage given below :
A colloid is a heterogeneous system in which a substance is dispersed (dispersed phase) as fine particles in another substance called dispersion medium.
Their particle size is intermediate between that of pure solutions (less than 1 nm ) and suspensions (greater than 1000 nm ).
They are known for interesting properties such as enormous surface area, Tyndall effect, Brownian motion etc.
They are widely used in industries and day to day life.
Some prominent uses of colloids are those in smoke precipitators, purification of water, medicines, cleansers etc.
Stability of a colloid is intermediate between that of a solution and suspension. This stability can be attributed to _____________
A. Presence of charge on the particles of dispersed phase.
B. Prolonged mechanical stirring.
C. Solvation by the dispersion medium.
D. Brownian Motion.
E. Dialysis
Choose the correct answer from the options given below :

When phenol is treated with chloroform in the presence of \(NaOH\), the major product formed is ?

Which of following is a correct statement ?

The rate constant of a reaction increases from \(0.02 \mathrm{~s}^{-1}\) to \(0.04 \mathrm{~s}^{-1}\) when the temperature is raised from 500 K to 600 K.
The activation energy \(\left(E_a\right)\) of the reaction is
(Given: \(\log _{10} 2=0.3010\) )

Read the passage carefully and answer the Questions
\(KMnO _4\) is prepared by the fusion of \(MnO _2\) with an alkali metal hydroxide and an oxidizing agent like \(KNO _3\) to give a dark-green manganate ion which disproportionate to give permanganate as follows.
\(\begin{array}{l}2 MnO _2+4 KOH + O _2 \rightarrow 2 K_2 MnO _4+2 H _2 O \\ 3 K_2 MnO _4+4 H ^{+} \rightarrow 2 KMnO _4+ MnO _2+2 H _2 O \end{array}\)
On heating \(K _2 MnO _4\) decomposes at 513 K to give \(K _2 MnO _4\). Permanganate ion is tetrahedral and diamagnetic
Acidified \(KMnO _4\) acts a strong oxidizing agent which oxidizes oxalic acid, ferrous ions, nitrite ion and iodides.
Oxidation states of Mn in \(MnO _2, KMnO _4\) and \(K _2 MnO _4\) are

In the circuit shown in the figure, the ac source gives a voltage of V = 10 cos (500t). The ammeter reading will be :

Arrange the following electrolytes in the increasing order of van't Hoff factor (i) for complete dissociation of solute.
(A) \(\left[ Co \left( NH _3\right)_6\right] Cl _3\)
(B) \(MgCl _2\)
(C) \(K _4\left[ Fe ( CN )_6\right]\)
(D) KCl
Choose the correct answer from the options given below:

The work function of calcium is 2.14 eV. Find the threshold frequency for calcium.

What is the Werner secondary valence in complex \([CoCl(NH_3)_5]^{2+}2Cl^-\) ?

On connecting a device X in a series circuit with a battery and a resistor, a current passes through the circuit. On reversing the polarity of the battery, the current in the circuit drops to almost zero. The device X may be a

\(\int_0^2 x(2-x)^n d x\) is equal to