BITSAT Chemistry Test - 7 - JEE MCQ

The heat exchanged in a reaction at constant temperature and pressure is known as enthalpy.

According to Aufbau principle the orbitals of lower energy are filled first followed by higher energy orbitals. Hence, the correct explanation is 1s², 2s² 2p⁶ .

For an ideal gas Joule-Thomson coefficient is zero. Because van der Waal’s forces of attraction are negligible and there is no expenditure of energy in overcoming these forces of attraction.

CF₃COOH is the strongest acid due to greatest - I effect of fluorine atom among chlorine and methyl.

 The isomerism exhibited is metamerism. This is exhibited by the members of same homologous series due to different alkyl groups, attached to functional group.

 The hydrocarbons having the highest boiling point will have the maximum number of carbon atoms in its molecules. Here, hydrocarbon C has the highest boiling point of -0.6°C, therefore, it have the maximum number of carbon atoms in its molecule.

The correct order of dipole moment of HF, H₂S and H₂O is HF < H₂S < H₂O

A mole of any substance is related to number of particles, volume of gaseous substanceand mass of a substance.

According to Bronsted theory an acid is a substance that donates proton and a base is a substance that accept protons. Hence, base is proton acceptor.

The Baeyer’s reagent is alkaline KMnO₄ solution which is used for detection of unsaturation.

Lyophobic sols are the colloidal solution in which particles of dispersed phase has less affinity towards dispersion medium. They are highly unstable.
Lyophillic sols are the colloidal solution in which particles of dispersed phase has great affinity towards dispersion medium.
The greater stability of lyophillic sols is due to high hydration in the solution, which means lyophillic colloids are extensively solvated. 

The phenomenon of scattering of light by colloidal particles as a result of which the path of the beam becomes visible is called a tyndall effect. Size of colloidal particles may range from 1 to 1000 nm.
Tyndall effect is observed only when the following conditions are satisfied:-
(i) The diameter of the dispersed particles is not much smaller than the wavelength of the light used.
(ii) The refractive indices of dispersed phase and dispersion medium differ greatly in magnitude. if the refractive indices of the dispersed phase and dispersion medium are almost similar in magnitude, then there will be no scattering of light and hence, therefore, no tyndall effect is observed.

Tyndall effect is related to scattering of light by colloidal particles and not dependent on charge.

When a gas is adsorbed on the surface, the freedom of movement of its molecules becomes restricted. This causes decrease in the entropy of the gas after adsorption, .i.e. ΔS becomes negative and for spontaneity ΔG (-ve), ΔH has to be highly (-ve).

According to Freundlich Isotherm


Given:
P=2 atm, k=2
Put these values in equation (1)

=2 log 2
= 2 log 2
= log 4
⇒ x/m = 4
Here x is the adsorbed mass of dispersion phase and m is the mass of dispersion medium.

Assuming the formation of a monolayer of the adsorbate on the surface of the adsorbent.
It was derived by Langmuir, that the mass of the gas adsorbed per gram of the adsorbent is related to the equilibrium pressure according to the equation,

where,
x is the mass of the gas adsorbed on m gm of the adsorbent
P is the pressure
a and b are the constants

The stability of lyophilic colloids is due to two main factors.

• Presence of charge -that can be either positive or negative charge.
• Solvation of colloidal particles

C+O₂→CO₂ ΔH=x
We get above equation by addtion of 2 and 3

x = y + z

T = 500K

K_p = 10² = 100

The free energy change for any process is given as:
ΔG = ΔH - TΔS
Here, ΔH is a change in enthalpy, ΔS is a change in entropy and ΔG is a change in Gibbs free energy. For any process to be spontaneous, ΔG is negative. ΔH and ΔS can be positive or negative, but ΔG must be negative.

2Mg+SiO₂→2Mg_O+Si
ΔH=H₂−H₁
2(−34.7)−(−48.24)
=−21.16 KJ

Gibbs energy is that part of the total energy of a system, which can be converted into useful work. It also predicts the spontaneity of the process. If for a process, ΔG is negative, the process is spontaneous.
According to Gibbs-Helmholtz equation,
ΔG=ΔH−TΔS
TΔS=ΔH−ΔG

ΔG=ΔH−TΔS
At equilibrium,  ΔG=0
⇒0=(170×10³ J)−T(170 JK⁻¹)
⇒T=1000 K
For spontaneity,  ΔG is −ve, which is possible only if T > 1000K.

PE required=mgh=100 × 10 × 500=5 × 10⁵ J
Let W gm of glucose required

or
or 

We know,

Hence, this is the correct option.

Since both ions, M^a+ and M^b+ have same magnetic moment, say 5.916, it means both have same number of unpaired electrons, i.e 5. It is possible if the values of 'a' and 'b' are 3 and 1, respectively. Thus, the electronic configurations of M^a+ and M^b+ are:
M^a+ = 3s², 3p⁶, 3d⁵
Mb+ = 3d⁶, 4s¹
It is clear from the above electronic configurations that M^a+ is more stable than M^b+ because of half-filled d-orbital.

1) IF₇ has 7 shared pairs, no lone pairs and sp³d³ hybridisation.
2) XeF₆ has 6 shared pairs, one lone pair and sp³d³ hybridisation.
3) SF₆ has 6 shared pairs, no lone pairs and sp³d² hybridisation.
4) ClF₅ has 5 shared pairs, one lone pair and sp³d² hybridisation.
Hence, (B) is the correct answer.

K = 3.3 x 10^-4 s^-1
(It is clear from unit of rate constant that the given reaction is a first order reaction.)
Now, according to the first order reaction:

In the compound K[Cr(CN)4(NH3)(NO)], Cr has +4 oxidation state; therefore, the number of unpaired electrons is 2.
So, magnetic moment = BM