Chemistry: CUET Mock Test - 3 - CUET MCQ

As reaction is zero order

Rate = k[NH₃]⁰

Rate = k

Rate =

ΔH/Δt = 3k
= 3 × 2.5 × 10^–4
= 7.5 × 10^–4 mol L^–1 s^–1

The molecularity of an elementary reaction is the number of reactant molecules involved in the rate-determining step. In the reaction 2NO+O₂→2NO₂ , two molecules of NO and one molecule of O₂(total of three molecules) participate in the elementary step. Thus, the molecularity is three.

An emulsion is a type of colloid in which one liquid is dispersed in another immiscible liquid in the form of small droplets.
Hair cream is an example of an emulsion where oil droplets are dispersed in water. Paint can also be classified as an emulsion or a suspension depending on the type of paint.
Cheese, on the other hand, is a type of colloid where solid particles are dispersed in a liquid. Smoke is an aerosol, which is a type of colloid where solid or liquid particles are suspended in a gas.

Tincture of iodine is NOT a colloid. A colloid is a mixture where particles (1–1000 nm) are dispersed in a medium and scatter light. Milk (emulsion), jelly (gel), and fog (aerosol) are colloids. Tincture of iodine is a true solution of iodine in alcohol, with molecular-sized particles that do not scatter light. Colloids can be separated by centrifugation (e.g., fat from milk), but true solutions cannot.

The Tyndall effect is the scattering of light as a light beam passes through a colloid. This effect is used to determine whether a mixture is a true solution or a colloid. Milk, starch solution and emulsions show Tyndall effect whereas sugar solution doesn’t show Tyndall effect.

Assume K = PhCOCH₃ (acetophenone, based on aldol condensation).

Option A:
Alkaline potassium permanganate (KMnO₄) is a strong oxidizing agent. It can oxidize ketones under strong conditions by breaking the carbon chain next to the carbonyl group.
For the compound PhCOCH₃ (acetophenone), oxidation with alkaline KMnO₄ followed by acidification (H⁺) gives benzoic acid (PhCOOH) and small fragments.
So, this is correct because the methyl group attached to the carbonyl gets oxidized to form benzoic acid.

Option B:
The iodoform test detects methyl ketones (a CH₃ group attached to a carbonyl group) or compounds that can be oxidized to methyl ketones.
PhCOCH₃ is a methyl ketone, so it gives a positive iodoform test and forms a yellow precipitate of iodoform (CHI₃).
This is incorrect.

Option C:
The reaction of benzene with benzoyl chloride in the presence of a Lewis acid (Friedel-Crafts acylation) gives benzophenone (PhCOPh), not acetophenone (PhCOCH₃).
So, this is incorrect.

Option D:
Tollens' test is used to detect aldehydes, not ketones. Since PhCOCH₃ is a ketone, it does not react with Tollens' reagent.
This is also incorrect.

Given:

Compound J upon reaction with KOH gives benzyl alcohol + L means it is a Cannizaro reaction and in the Cannizzaro reaction if one compound is benzyl alcohol then L will be acid i.e benzoic acid 
Ph - COO^-K⁺ so the J compound will be benzaldehyde

Now K when treated with KOH gives M means aldol condensation

As we know our J and K compound let's find I which is an alkene

Now we know that 3° alcohol forms alkene by hydrolysis which is our compound H. means our compound H will be

Compound H is formed by the reaction of

Compound "I" is formed when compounds J and K compound reacts with each other. 

∴ Compound "I" is

∴ Option 1 is correct.

We know J is

When "J" was treated with acetic anhydride in the presence of salt of an acid (The reaction taking place will be a perkin reaction)

and the product is cinnamic acid

Following are the structures of compounds J, K & I

and "L" benzoic acid ie. Ph - COO^-K⁺ 
Hence the correct option is 4

Colligative properties depend on the number of solute particles and are independent of the nature of the solute. Osmotic pressure, boiling point elevation, and freezing point depression are examples.

(A) is correct because Raoult's law applies only on ideal solutions
(B) is correct as Raoult’s law states that the vapor pressure of a solvent in a solution is directly proportional to the mole fraction of the solvent.
(C) is incorrect because Raoult’s law is not strictly limited to non-volatile solutes, and it can apply to solutions with volatile solutes, though deviations may occur for highly volatile solutes.
(D) is incorrect because Raoult's law holds true primarily for ideal solutions, where there is no deviation in behavior between the solute and solvent.

Colligative properties depend on the number of solute particles, ideal solutions have similar intermolecular forces, and osmosis is the movement of solvent from low to high concentration.

(A) is correct because the molal freezing point depression constant is a property of the solvent and varies depending on the solvent.
(B) is incorrect because the molal freezing point depression constant is not the same for all solvents; it is specific to each solvent.
(C) is correct because the molal freezing point depression constant is used to calculate the depression in freezing point, which depends on the concentration of the solute.
(D) is incorrect because K_f is a solvent-specific constant, independent of the amount or identity of the solute.

ilver in the form of Ag⁺ is colourless. For transition metal ions to exhibit color, their metal ions must have incompletely filled (n-1)d orbitals.

Ag⁺ =4d¹⁰,5s⁰

Ag⁺ has completely filled d orbitals hence is colourless.

Zn²⁺ has completely filled d-orbitals and there are no vacant d-orbitals for the transition of electrons, hence it is colourless.

Till d⁵ unpaired electron are increasing so maximum bonding as unpaired electron take part in bonding. So melting point increases till d⁵ then start decreasing due to pairing which decreases metallic bond strength and thus melting point.

Cr(24) = [Ar]3d54s1
Since (CO) is strong ligand, in Cr(CO)6 none of the electron is unpaired. Therefore ‘spin only’ magnetic moment is zero.

The acetylacetonate (acac) forms six membered ring as follows:

Correct Answer : a

Explanation : NO in brown ring complex has +1 oxidation state.

Let oxidation state of Fe be x.

Since the overall charge on the coordination sphere, [Fe(H2O)5NO+]  is +2, the sum of oxidation states of all elements in it should be equal to +2.

Therefore, x+1=+2

or, x=+1 

Hence, the oxidation state of iron in the brown ring complex is +1.

In electrolysis of a fused salt, the weight deposited on electrode will not depend or temperature.

In this Cl^– will oxidise to give Cl₂ Na⁺ water reduction potential has higher potential than that of water reduction potential, so water will reduce to give H₂.

Above equilibrium can explain the formation of given product, hence reaction must proceed by E1 cb mechanism

In the structure two phenyl groups are attached to the amino group, hence the name Diphenyl amine.

Alkanes on free radical halogenation produce a mixture of haloalkanes and not alcohols. Alcohols can be prepared from alkenes by acid catalysed hydration and hydroboration-oxidation or from reduction of aldehydes.

In a two-dimensional square close packed structure, each sphere is in contact with 4 of its adjacent spheres. Hence, it has coordination number 4.

Two-dimensional hexagonal close packed structure are formed when one row of a one-dimensional structure is placed below another in such a way that spheres of second row fit in the depressions of the first row and thereby creating triangular voids between them.

For any process, the change in Gibbs free energy (ΔG) is given by the equation,
ΔG = ΔH – TΔS
Where ΔH is the enthalpy change, ΔS is the entropy change and T is the absolute temperature.

Group 16 of the periodic table consists of five elements viz., Oxygen (O), Sulfur (S), Selenium (Se), Tellurium (Te) and Polonium (Po). The elements of this group are commonly known as the oxygen family after the name of its first member.