Additin of sodium hydroxide solution to a weak acid (HA)results in a buffer of pH 6. If ionition constant of HA is 10$$-$$5, the ratio of salt to acid concentration in the buffer solution will be :

pKa of a weak acid (HA) and pKb of a weak base (BOH) are 3.2 and 3.4, respectively. The pH of their salt (AB) solution is :

The group having isoelectronic species is:

If the shortest wavelength in Lyman series of hydrogen atom is A, then the longest wavelength in Paschen series of He+ is :

The electron in the hydrogen atom undergoes transition from higher orbitals to orbital of radius 211.6 pm. This transition is associated with :

The radius of the second Bohr orbit for hydrogen atom is: (Planck’s Const. h = 6.6262 × 10-34 Js; mass of electron = 9.1091 × 10-31 kg; charge of electron (e) = 1.60210 × 10-19 C; permittivity of vacuum ($${\epsilon }_0$$) = 8.854185 × 10-12 kg-1 m-3 A2)

The electronic configuration with the highest ionization enthalpy is :

Which one of the following is an oxide?

Consider the following ionization enthalpies of two elements 'A' and 'B' . .tg {border-collapse:collapse;border-spacing:0;} .tg td{font-family:Arial, sans-serif;font-size:14px;padding:10px 5px;border-style:solid;border-width:1px;overflow:hidden;word-break:normal;border-color:black;} .tg th{font-family:Arial, sans-serif;font-size:14px;font-weight:normal;padding:10px 5px;border-style:solid;border-width:1px;overflow:hidden;word-break:normal;border-color:black;} .tg .tg-p7ly{font-weight:bold;font-size:20px;text-align:center} .tg .tg-4kyz{font-size:20px;text-align:center} Element Ionization enthalpy (kJ/mol) 1st 2nd 3rd A 899 1757 14847 B 737 1450 7731 Which of the following statements is correct ?

In which of the following reactions, hydrogen peroxide acts as an oxidizing agent ?

A metal crystallises in a face centred cubic structure. If the edge length of its unit cell is ‘a’, the closest approach between two atoms in metallic crystal will be :

The increasing order of the reactivity of the following halides for the SN1 reaction is :

The major product of the following reaction is :

In the following reaction sequence : The compound I is :

The major product of the following reaction is :

Which of the following compounds will not undergo Friedel Craft’s reaction with benzene ?

The major product obtained in the following reaction is :

Which of the following, upon treatment with tert-BuONa followed by addition of bromine water, fails to decolorize the colour of bromine?

3-Methyl-pent-2-ene on reaction with HBr in presence of peroxide forms an addition product. The number of possible stereoisomers for the product is :

The rate of a reaction A doubles on increasing the temperature from 300 to 310 K. By how much, the temperature of reaction B should be Increased from 300 K so that rate doubles if activation energy of the reaction B is twice to that of reaction A.