The strongest reducing agent amongst the following is :
(Given that \(€^{\circ}_{Ni^{2+}/Ni} = -0.25\text{ V}\), \(€^{\circ}_{Cu^{2+}/Cu} = 0.34\text{ V}\), \(€^{\circ}_{Pb^{2+}/Pb} = -0.13\text{ V}\), \(€^{\circ}_{Cr^{3+}/Cr} = -0.74\text{ V}\))

Arrange the following in the decreasing order of their magnetic moment values:
A. Sc (Z=21)
B. V (Z=23)
C. Mn (Z=25)
D. Fe (Z=26)
E. Ni (Z=28)
Choose the correct answer from the options given below:

Read the passage carefully and answer the questions
The chemical reactions proceed at different rates which depend on various factors like concentration, temperature, etc. Rate law is an expression which relates the rate of reaction with concentration of various reacting species in the reaction. For a first order reaction, the concentration of the reactant after time \(t\) is related with its initial concentration by the relation, \(C=C_0 e^{-k t}\). The rate constants for different orders have different expressions. For a first order reaction, \(k=\frac{2.303}{t} \log \frac{a}{a-x}\), where \(a\) is the initial concentration and \(x\) is the extent of reaction.
A reaction which is first order with respect to the reactant \(A\) has a rate constant of \(6 min^{-1}\). If the reaction is started with \([A]=5.0 mol L ^{-1}\) when would \([A]\) reach the value of \(0.05 mol L ^{-1}\)

Which of the following is not an expression of Dalton's law of partial pressures?

Which of the following statements, with reference to a solution, are correct?
(A) The osmotic pressure of the solution is proportional to the molarity of the solute.
(B) The elevation of the boiling point (\(\Delta T_b\)) is directly proportional to the molal concentration of the solute in a solution.
(C) The unit of \(K_b\) is \(\mathrm{K} \mathrm{kg}^{-1} \mathrm{~mol}^{-1}\).
(D) \(\Delta T_b=T_b^0-T_b\).
Choose the correct answer from the options given below:

Read the passage carefully and answer the questions
The resistance ( \(R\) ) of an object is given by the expression \(R=\rho \frac{l}{A} .\)
The inverse of \(R\) is called conductance and the inverse of \(\rho\) is called conductivity or specific conductance represented by \(\kappa\).
The conductivity depends upon the nature of the material (insulator, semiconductor or conductor) and the temperature of the substance.
Similarly, the conductance due to the ions present in the solution (ionic conductance) depends upon the nature of the electrolyte, size of ions, the nature of the solvent and the temperature.
Molar conductivity ( \(\Lambda_m\) ) of a solution at a given concentration is the conductance of volume \(V\) containing one mole of electrolyte kept between two electrodes of area \(A\) and unit distance apart.
It is given by the expression \(\Lambda_m=\kappa V .\)
Molar conductivity increases with decrease in concentration and when concentration approaches zero, it is called limiting molar conductivity.
The decrease is linear for a strong electrolyte. However, for a weak electrolyte the change is gradual at higher concentrations and sharp near zero concentration.
Using limiting molar conductivity values of strong electrolytes we can calculate the limiting molar conductivity of weak electrolytes using Kohlrausch law of independent migration of ions.
From molar conductivity and limiting molar conductivity we can determine the degree of dissociation \(\left(\frac{\Lambda_m}{\Lambda_m^0}\right)\) and the ionization constant of a weak acid.
Select the correct statement.

Fehling solution gives red precipitate with.....

The construction of the first recombinant DNA emerged from linking a gene encoding antibiotic resistance with a native plasmid of __________.

A positively charged glass rod attracts an object. The object must be :

Arrange the following amines in increasing order of their basic strength in the gaseous phase
(A) \(\mathrm{C}_6 \mathrm{H}_5 \mathrm{NH}_2\)
(B) C\(_6\)\(\mathrm{H}_5CH\)\(_2\)\(\mathrm{NH}_2\)
(C) (CH\(_3\))\(_3\)N
(D) CH\(_3\)\(\mathrm{NH}_2\)
Choose the correct answer from the options given below:

The radius of the first orbit in Bohr's hydrogen atom is 0.53\(\text{\AA}\). The radius of fourth orbit of this atom will be:

Which of the following is NOT an example of alien species invasions?

The average value of a.c. over a full cycle in an ac circuit is : (Given \( I_0 \) = Peak current)