CUET UG Chemistry: Mock Test - 5 Free Online Test 2026

Outer electron configuration of Ti = 3d²4s²
So, Maximum O.S. of Ti = +4
Outer E.C. of V = 3d³4s²
So, Maximum O.S. of V = +5 Outer E.C. of Mn = 3d⁵4s²
So, Maximum O.S. of Mn = +7
Outer E.C. of Cu = 3d¹⁰4s¹
So, Maximum O.S. of Cu = +2
So, correct option is : A-II, B-III, C-I, D-IV

Concentration directly affects the rate of reaction as described by the rate law expression — rate = k[A]ᵐ[B]ⁿ (II). Temperature increases the rate exponentially as described by the Arrhenius equation, since more molecules acquire the activation energy at higher temperatures (III). A catalyst increases the rate of reaction by providing an alternative pathway of lower activation energy, without being consumed (I). Surface area plays a critical role in heterogeneous reactions — finely divided solids expose more surface area, increasing the frequency of effective collisions (IV).

Activation energy (Ea) is the minimum amount of energy that reacting molecules must possess for a collision to result in a chemical reaction (I). The Arrhenius equation, k = Ae^(−Ea/RT), mathematically relates the rate constant k to temperature T and activation energy (II). Collision theory explains that reactions occur when molecules collide with sufficient energy and proper orientation — only such effective collisions lead to product formation (III). The integrated rate equation is derived by integrating the differential rate law and is used to determine the half-life of a reaction and concentration at any given time (IV).

Cu has positive value in 3d series.

In the first transition series, the standard electrode potential ((E0M2+/M) indicates the ease with which a metal can be reduced to its metallic form from its ion in aqueous solution. A positive value for (E⁰_M²⁺/M) means that the reduction process is favorable, and the metal is relatively less reactive compared to those with negative values.

Among the given options:

Chromium (Cr) has a negative standard reduction potential.
Vanadium (V) also has a negative value.
Copper (Cu) has a positive standard reduction potential ((E⁰_Cu²⁺/Cu = +0.34 V)), meaning it is readily reduced to its metallic state.
Nickel (Ni) has a negative standard reduction potential.

= 0.34 V

= –0.90 V

= –1.18 V

= = –0.25 V

• The spin-only magnetic moment is given by μ = √[n(n + 2)] BM, where n is the number of unpaired electrons.
• Cr ([Ar] 3d⁴ 4s¹) forms Cr²⁺ by losing two electrons: [Ar] 3d⁴.
• In a high-spin d⁴ configuration, there are 4 unpaired electrons (n = 4).
• Calculate: μ = √[4(4 + 2)] = √24 ≈ 4.90 BM.
• Correct option: B

The correct answer is Square planar structure
Coordination Number: The coordination number of the nickel ion (Ni²⁺) in the complex [Ni(CN)₄]^2- is 4. This is because there are four cyanide ions (CN-) surrounding the central metal ion.

Nature of Ligands: Cyanide ions (CN-) are strong-field ligands. In CFT, strong-field ligands typically lead to the pairing of d-electrons and the formation of low-spin complexes.

Electron Configuration of Ni²⁺: The electron configuration of the nickel ion (Ni²⁺) is [Ar] 3d⁸. In the presence of strong-field ligands, the electrons fill the lower-energy orbitals before pairing, leading to a low-spin configuration.

Geometry: In a square planar structure, the ligands approach the central metal ion along the x, y, and z axes, resulting in a flat, square arrangement. This is the favored geometry for low-spin d8 complexes with strong-field ligands.

Conclusion:-

According to CFT, [Ni(CN)₄]^2- is expected to have a square planar structure due to the combination of a coordination number of 4 and the strong-field nature of the cyanide ligands.

Analyzing the statements: -

(A) True: A higher standard electrode potential (`E⁰`) indicates a greater tendency for reduction (gain of electrons). 

(B) False: A negative `E⁰` indicates a lower tendency for reduction (more likely to lose electrons).

(C) True: In a galvanic cell, electrons flow from the anode (where oxidation occurs) to the cathode (where reduction occurs) through the external circuit.

(D) False: In an electrolytic cell, the cathode is the site of reduction, not oxidation.

Correct statements: (A) and (C).

Correct option: A

Analyzing the statements:
- (A) True: Standard electrode potential (`E⁰`) is measured under standard conditions (1 M concentration, 1 atm pressure, 25°C).
- (B) False: The standard cell potential is `E⁰_cell = E⁰_cathode - E⁰_anode`.
- (C) False: A positive `E⁰` indicates a greater tendency to gain electrons (reduction), not lose electrons.
- (D) True: `E⁰` measures the tendency of a species to gain electrons (reduction potential).
Correct statements: (A) and (D).
Correct option: C

Oxidation involves the loss of electrons, and reduction involves the gain of electrons. An oxidizing agent is reduced, and a reducing agent is oxidized.

Analyzing the statements:
- (A) False: The rate of a reaction is not constant; it depends on factors like concentration and temperature.
- (B) True: The rate of a reaction is defined as the change in concentration of reactants or products per unit time.
- (C) True: Reaction rate generally increases with temperature due to increased molecular collision frequency and energy.
- (D) False: The rate is affected by the concentration of reactants (rate law).
Correct statements: (B) and (C).
Correct option: B

At cathode
4H₂O + 4e^– → 4H₂ + 4OH^–
At anode
2H₂O → 4H⁺ + O₂ + 4e^–
Thus at cathode we will get H₂ whereas at anode we will get O₂.

The correct answer is option A
rate=k[NO]₂[O₂]
As, C = n/V
On making the volume half, concentration doubles and rate of reaction becomes eight times.
 

The correct answer is Option A.

E represents the energy of activation which implies it is the energy below which colliding molecules will not react Arrhenius equation gives the dependence of the rate constant k of a chemical reaction on the absolute temperature T (in Kelvin), where A is the pre-exponential factor (or simply the prefactor), Ea is the activation energy, and R is the Universal gas constant:
By Arrhenius equation, k=Ae^-Ea/RT

Since the configuration of Fe³⁺ ion is (argon ) 3d⁵,which contains maximum number of unpaired electrons, hence more will be paramagnetic behavior.

Rate of reaction in E2 reaction depends on acidity of β—H as well as steric hindrance at β-carbon. When X is F, acidity is maximum and there is less steric hindrance at less substituted β-carbon.

It forms resonance stabilised carbanion after abstraction of β—H hence, favours the most to E1cb mechanism.

The Isomers of C₃H₆O include:

Hence we can see that a total of 11 isomers of C₃H₆O are possible.

• Isobutyraldehyde is the chemical compound with the formula (CH₃)₂CHCHO.
  
• It is an aldehyde, isomeric with n-butyraldehyde.
• Isobutyraldehyde is manufactured, often as a side-product, by the hydroformylation of propene. Its odour is described as that of wet cereal or straw.

The IUPAC name of (CH₃)₂CHCHO is 2-methylpropanal and its chemical name is Isobutyraldehyde.

Alcohol is the group in which (carbonyl) group is not present. Aldehydes, ketones and carboxylic acids all have a carbonyl group present in them. Aldehydes have group, ketones have a group and carboxylic acids have a group.

Hence A is correct.

The IUPAC name of tertiary methyl amine is N,N-Dimethyl-methanamine.

Glycogen

Haemoglobin

The peptide linkage

Secondary structure of protein