When an electric discharge is passed through hydrogen gas, the hydrogen molecules dissociate to produce excited hydrogen atoms. These excited atoms emit electromagnetic radiation of discrete frequencies which can be given by the general formula

v= 109677 [1/ni ² - 1/nf ² ]

What points of Bohr's model of an atom can be used to arrive at this formula? Based on these points derive the above formula giving description of each step and each term.

Find out the number of following orders which are INCORRECT against the mentioned properties:

(i) Ortho hydrogen > Para hydrogen (Stability at low temperature)

(ii) Ethanol > Glycerol (Viscosity)

(iii) D₂ < He (Boiling point)

(iv) HF > H₂O (Melting point)

(v) H₃BO₃ > BF₃ (Melting point)

(vi) NH₃ < SbH₃ (Boiling point)

(vii) H₂O₂ > H₂O (Strength of hydrogen bond)

(viii) H₂O < D₂O (Freezing point)

(ix) $H{F}_2^{\Theta }$  < HF (Strength of hydrogen bond)

(x) D₂O < H₂O (Bond energy)

Consider the following reaction:
(A substituted phenol reacts with H? and CrO?Cl to produce product 'P'.)
The product ‘P’ gives positive acetyl chloride test. This is because of the presence of which of these –OH group(s)?
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The number of radial land angular nodes in 4d orbital are, respectively

The spin-only magnetic moment value of species is________× 10^-2 BM. (Nearest integer)

[Given: <!-- [if gte mso 9]><xml> </xml><![endif]-->  $\sqrt[]{3}=1.73]$

Which of the following relation is not correct?