When benzene diazonium chloride is treated with halogen acid in the presence of copper powder, the reaction is referred to as

Answer the question on the basis of passage given below:
Adsorption is the phenomenon of attracting and retaining the molecules of a substance on the surface of a solid resulting into a higher concentration on the surface than in the bulk. The substance adsorbed is known as adsorbate and the substance on which adsorption takes place is called adsorbent. In physisorption adsorbate is held to the adsorbent by weak van der Waals forces and in chemisorption by strong chemical bond.
In coagulation of a positive sol, the flocculating power will be in the order:
A. \(PO _4^{3-}\)
B. \(Cl ^{-}\)
C. \([ Fe ( CN )]^{3-}\)
D. \(SO _4^{2-}\)
Choose the correct answer from the options given below:

Which transition metal group is known as coinage metals?

Read the passage carefully and answer the questions:
The degeneracy of the \(d\) orbitals has been removed due to ligand electron-metal electron repulsions in the octahedral complex to yield three orbitals of lower energy, \(t_2\), set and two orbitals of higher energy, \(e_g\) set. This splitting of the degenerate levels due to the presence of ligands in a definite geometry is termed as crystal field splitting and the energy separation is denoted by \(\Delta_0\). Thus energy of the two \(e_g\) orbitals will increase by \((3 / 5) \Delta_0\) and that of three \(t_{2 g}\) will decrease by \((2 / 5) \Delta_0\). The crystal field splitting \(\Delta_{\circ}\) depends upon the field produced by the ligand and charge on the metal ion. Some ligands are able to produce strong fields, in which case the splitting will be large, whereas others produce weak fields and consequently result in small splitting of \(d\) orbitals. Relative magnitude of crystal field splitting energy \(\Delta_0\) and pairing energy, \(P\) (energy required for electron pairing in a single orbital) determine the formation of low spin ( \(\Delta_{\circ}>P\) ) or high spin ( \(\Delta_{\circ}<P\) ) complex. In tetrahedral coordination entity formation, the d-orbital splitting is inverted and is smaller as compared to the octahedral field splitting. The crystal field theory attributes the colour of the complex to \(d-d\) transition of the electron. The colour of the coordination compounds depends on the crystal field splitting. In the absence of ligand, crystal field splitting does not occur and hence the substance is colourless.
What will be the crystal field splitting energy for tetrahedral \(\left[ CoCl _4\right]^{2-}\) if its value for octahedral \(\left[ CoCl _6\right]^{4-}\) is \(18,000 cm^{-1}\) ?

Match List I with List II

List 1	List 2
A. Lanthanum	I. \(+3,+4\)
B. Praseodymium	I. +3
C. Neodymium	III. \(+2,+3,+4\)
D. Samarium	IV. \(+2,+3\)

Choose the correct answer from the options given below:

In p-type semiconductors, the conductivity is due to:

The correct order of dipole moment of the different methyl halides is :

Alien DNA can be introduced in the animal host cell by :

Identify the major product in the following reaction :
\(CH_3-CH\left(CH_3\right)-CH_2 Br \xrightarrow{\text { aq. } OH^{-}} \text {? }\)

If the objective function \(Z=p x+q y, p>0, q>0\) of a linear programming problem attains its optimal value at the points \((4,7)\) and \((5,5)\) and \(pq =50\) then:

What is the structural formula for Freon-12.

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

Match List-l with List-ll
Let \(A\) be any invertible square matrix. Then

List-l	List-ll
(A) \(A-A^T\)	(I) \(|A| A^{-1}\)
(B) \(A A^T\)	(II) Skew-symmetric
(C) \(\operatorname{det}\left(A^{-1}\right)\)	(III) Symmetric
(D) \(\operatorname{adj} A\)	(IV) \([\operatorname{det}(A)]^{-1}\)

Choose the correct answer from the options given below :