A square planar complex is formed by hybridisation :

The unit for molar conductivity is

The actual density of a crystal of NaCl is observed to be lower than the expected value. It is caused due to the presence of :

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, \(t_{2 g}\) 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 \(\Delta_0\) 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 \(\Delta_{\circ}\) 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 \(18,000 cm^{-1}\) ?

What are the products of the following reaction in neutral solution?
\(\mathrm{MnO}_4^{-}+\mathrm{S}_2 \mathrm{O}_3^{2-}+\mathrm{H}_2 \mathrm{O} \rightarrow ?\)

According to Alexander Zaitsev the most preferred product for dehydrohalogenation of 2-Bromopentane will be :

On boiling with concentrated \(\text{HBr}\), phenyl ethyl ether will give:

The reduction of cyclohexanone with \(NaBH _4\) produces

A plane concave lens of glass (\( \mu = 1.5 \)) has a radius of curvature of its curved face 50 cm. The power of the lens is :

Benzene ring in phenol is expected to give the characteristic substitution or replacement reactions i.e. halogenation, nitration, sulphonation, alkylation etc. In these reactions, the attacking reagent is electrophile. The phenolic group activates the ortho and para positions in the ring due to conjugation. Disubstitution reactions are quite fast as the electron density in the ring has increased considerably. Phenols do not respond to nucleophilic substitution reactions as it is influenced by phenolic group.
Victor Meyer test gives following observations. Match List I with List II:

List-I	List-II
A. Blood red colouration	I. Tertiary alcohol
B. Blue colouration	II. Phenols
C. Colourless solution	III. Primary alcohol
D. Violet colouration with \(\text{FeCl}_3\)	IV. Secondary alcohol

Choose the correct answer from the options given below:

If \(y=\sin ^{-1} x\), then \(\left(1-x^2\right) \frac{d^2 y}{d x^2}\) is equal to

Following are the wavelength of some constituents of the electromagnetic spectrum. The wavelength range that are used in Radar system for Aircraft navigation is :
(A) 1 mm to 700 nm
(B) 0.1 m to 1 mm
(C) 400 nm to 1 nm
(D) < \(10^{-3} nm\)
(E) > 1 m
Choose the correct answer from the options given below :

Match List-I with List-II

List-I	List-II
(A) Maximum kinetic energy of photoelectron	(I) No emission of electrons
(B) Photoelectric current	(II) slope of kinetic energy of electron-frequency graph
(C) Frequency of radiation < threshold frequency	(III) independent of intensity
(D) Plank's constant	(IV) independent of frequency