(CH₃)₃C–CHO does not undergo Aldol condensation due to

three electron donating methyl groups
cleavage taking place between —C— CHO bond
absence of alpha hydrogen atom in the molecule
bulky (CH₃)₃C—group

Solution

Aldol condensation is given by the compounds which contain α hydrogen atom. As the given compound does not contain α hydrogen atom. Hence it does not undergo aldol condensation.

Some of the properties of the two species, \(NO_{3}^{-}\) and H₃O⁺ are described below. Which one of them is correct?

Similar in hybridization for the central atom with different structures.
Dissimilar in hybridization for the central atom with different structures.
Isostructural with same hybridization for the central atom.
Isostructural with different hybridization for the central atom.

Solution

In \(NO_{3}^{-}\), nitrogen have sp² hybridisation, thus planar in shape. In H₃O⁺, oxygen is in sp³ hybridisation,thus tetrahedral geometry is expected but due to presence of one lp of electrons on central oxygen atom it is pyramidal in shape.

A solution is formed by diluting 250 ml. of 0.400 N H₂SO₄ with one litre of water. The normality of above formed solution is :

0.400N
0.899 N
0.040 N
0.080N

Solution

If 500 ml of gas A at 400 torr and 666.6 ml of B at 600 torr are placed in a 3 litre flask, the pressure of the system will be

200 torr
100 torr
550 torr
366 torr

Solution

An organic compound A containing nitrogen, on acid catalysed hydrolysis produces a water soluble organic compound B and a gaseous compound C. When methyl magnesium bromide is slowly added to A in 1 :1 ratio and hydrolysed, it produces a compound which can be obtained by dry distillation of the calcium salt of B. The compound A is

N-methylmethanamide
N-ethylmethanamide
acetonitrile
N, N-dimethylmethanamide

Solution

The catalyst used in the Wacker process of oxidation of ethyne to ethanal is

PdCl₂
V₂O₅
Nickel complexes
TiCl₄ and Al(CH₃)₃

Solution

Ethyne get converted to aldehydes and ketones when treated with an acidified aqueous solution of palladium chloride (PdCl₂) and cupric chloride (CuCl₂) in presence of air or oxygen. This method is known as Wacker’s process.

The kinetic energy of an electron in the second Bohr orbit of a hydrogen atom is [a₀ is Bohr radius] :

\(\frac{h^{2}}{4 \pi^{2}ma_{0}^{2}}\)
\(\frac{h^{2}}{16 \pi^{2}ma_{0}^{2}}\)
\(\frac{h^{2}}{32 \pi^{2}ma_{0}^{2}}\)
\(\frac{h^{2}}{64 \pi^{2}ma_{0}^{2}}\)

Solution

If the equilibrium constant of the reaction of weak acid HA with strong base is 10⁷, then pOH of the aqueous solution of 0.1M NaA is –

Solution

Z in the above reaction sequence is

CH₃CH₂CH₂NHCOCH₃
CH₃CH₂CH₂NH₂
CH₃CH₂CH₂CONHCH₃
CH₃CH₂CH₂CONHCOCH₃

Solution

The charge on colloidal particles is due to

presence of electrolyte
very small sizeof particles
adsorption of ions from the solution
None of these

Some statements about heavy water are given below:
(A)Heavy water is used as a moderator in nuclear reactors.
(B)Heavy water is more associated than ordinary water.
(C)Heavy water is more effective solvent than ordinary water.
Which of the above statements are correct?

(A) and (C)
(A) and (B)
(A), (B) and (C)
(B) and(C)

Solubility product of BaCl₂ is 4 × 10^-9 moles/litre. Its solubility would be :

1× 10^-27
1 × 10^-3
1 × 10^-7
1 × 10^-2

Solution

The above structural formula refers to

Which one of the following, statements is incorrect about enzyme catalysis?

Enzymes are mostly proteinous in nature.
Enzyme action is specific.
Enzymes are denaturated by ultraviolet rays and at high temperature.
Enzymes are least reactive at optimum temperature.

Solution

Enzymes are most reactive at optimum temperature. The optimum temperature for enzyme activity lies between 40°C to 60°C.

The element which is used as semiconductor is

Solution

Semiconductors are those solids which are good conductors of electricity at room temperature but behave as insulators at room temperature, e.g., silicon and germanium.

The correct order of heat of formation of halogen acids is

HI > HBr >HCl > HF
HF > HCl > HBr > HI
HCl > HF > HBr > HI
HCl > HBr > HF > HI

Solution

On moving from top to bottom of halogen group the bond dissociation energy of hydrogen halides decreases and so the heat of formation of halogen acids also decreases.

Which of the following has density greater than water?

Solution

Li, Na, K are lighter than water but Rb is heavier than water.

In the following reaction
\(C_{2}H_{5}OC_{2}H_{5} + 4[H] \overset{Red P + HI}{\rightarrow} 2X + H_{2}O\) , X is

ethane
ethylene
butane
propane

Solution

Identify the non polar molecule in the following compounds:

H₂
HCl
HF and HBr
HBr

Solution

In H₂, both atoms are identical, so the molecule is non polar.

An aqueous solution containing 1 gm of urea boils at 100.25ºC. The aqueous solution containing 3 g of glucose in the same volume will boil at (mol. wt. of urea = 60 and of glucose= 180) :

100.25ºC
100ºC
100.15ºC
100.50ºC

Solution

UnAttempted

0

Attempted

0

Correct

0

Wrong