Chemistry: CUET Mock Test - 1 - CUET MCQ

The elevation of the boiling point of a solution depends on the concentration of solute particles in the solution. The more the number of solute particles in the solution, the higher the elevation in boiling point.
Elevation in boiling point ∝ i × M
The given compounds and their respective aqueous solutions are

Order of elevation in boiling point

E > D > C > B > A

Molarity (M) is moles of solute per liter of solution.

• Mass of NaOH = 5 g, molar mass of NaOH = 40 g/mol (Na: 23, O: 16, H: 1).
• Moles of NaOH = 5 g / 40 g/mol = 0.125 mol.
• Volume = 450 mL = 450 / 1000 = 0.45 L.
• Molarity = 0.125 mol / 0.45 L = 0.278 M. Therefore, the molarity is 0.278 M.

onic conductance (electrolytic conductance) is the ability of ions to conduct electricity in a solution. Evaluating the statements:

• A: True. Ionic conductance depends on the nature of the electrolyte (e.g., strong vs. weak electrolytes).
• B: False. Ionic conductance is due to the movement of ions, not electrons.
• C: False. Ionic conductance is distinct from electronic conductance, which involves electron movement in conductors like metals.
• D: True. Ionic conductance increases with temperature due to increased ion mobility.
• E: True. The nature of the solvent (e.g., polarity, viscosity) affects ion solvation and mobility. Therefore, the correct statements are A, D, and E only.

1. Compound X which has C, H, and O and is unreactive to sodium means it is not an alcoholic compound.
2. it is also unreactive with Schiff's reagent means it is not a carbonyl compound. ​

​So the possible structure will be symmetrical ether.

So Z can be converted to Y. Now lets find out R. for that we will take the molecular weight of the acid.
→ R=?
→ C= 12
→ O= 16
→ O= 16
→ H= 1
So we get R + 45 we need 15 more for eq. wt. 60 which will be CH₃ = 12 + 1 + 3 = 15. So the acid will be CH₃COOH (Ethanoic acid) Now the wt is eq 60.
Now the overall reaction will be

Hence compound X is ether.

The overall reaction we get is as follows

From the reaction, the end product formed is Ethanoic Acid.
The acid formed with eq.wt.60 is Ethanoic Acid

Given,

The overall reaction formed is:

∴ Compound Y is ethyl iodide (C₂H₅I)

Given,

Overall Reaction is:

Comparing both, Compound Z is Ethanol (C₂H₅OH)

• Statement I: The boiling points of group 16 hydrides do not increase in the order H₂O < H₂S < H₂Se < H₂Te. The correct order is H₂O > H₂Te > H₂Se > H₂S due to hydrogen bonding in H₂O. Thus, Statement I is incorrect.
• Statement II: The boiling points do not strictly increase with molar mass because H₂O.has an anomalously high boiling point due to hydrogen bonding, despite its lower molar mass. For H₂S, H₂Se, and H₂Te, boiling points increase with molar mass due to stronger van der Waals forces, but H₂O is an exception. Thus, Statement II is incorrect.

Conclusion: Both statements are incorrect, so the correct answer is C.

The correct answer is Potassium pentacyanonitrosylferrate(II)
Metal/non-metal present outside the bracket is named first and name remains the same
Then name to the ligand first and number of ligands is used as suffix like if two ligands are present then it is
represented as di, 3 as tri, 4-tetra, 5-penta and 6 as hexa is given
Then metal ion present with the ligands here iron is present which is a coordination complex that is written as
ferrate
Calculate the oxidation number of the element written in roman manner in the last name.
x + (−1)5 = −3; x = −3 + 5 = 2 i.e. +2
Hence the name given Potassium pentacyanonitrosylferrate(II)
So, the IUPAC name of given compound is  Potassium pentacyanonitrosylferrate(II)

The correct answer is They serve as ligands binding to the metal ion

• In Werner's studies of coordination compounds, ammonia molecules serve as ligands, which are species that bind directly to the central metal ion through their lone pair of electrons.
• This binding illustrates Werner's concept of secondary valence, as the ammonia molecules contribute to the coordination number of the metal ion by forming coordinate covalent bonds.
• These ammonia ligands play a crucial role in determining the properties, geometry, and stability of the coordination compounds.

 So, Ammonia serve as ligands binding to the metal ion.

The correct answer is CoCl₃.6NH₃ (Yellow)
The compound CoCl₃.6NH₃ (Yellow) led to the precipitation of all three moles of chloride ions as AgCl when treated with excess silver nitrate, indicating that all chloride ions were ionically bound and not directly coordinated to the cobalt ion. In contrast, other compounds retained some of the chloride ions in solution, implying their direct coordination to cobalt and hence not precipitating as AgCl.
So, CoCl₃.6NH₃ (Yellow) compounds prepared by Werner had all chloride ions precipitated as AgCl when treated with excess silver nitrate.

The correct answer is Both B and C are correct
Werner used both the precipitation of chloride ions as silver chloride (AgCl) and measurements of electrical conductivity in solution to explore and distinguish the structural differences among cobalt(III) chloride complexes. These methods helped him to deduce the number of chloride ions directly coordinated to the cobalt ion and those present as free ions in the solution, which in turn provided insight into the structure of the complexes.
So, the correct answer is Both B and C are correct.

• A: True. Molarity (M) is defined as moles of solute per liter of solution (M = mol/L).
• B: False. Molarity depends on solution volume, which changes with temperature due to thermal expansion or contraction.
• C: False. Molarity is used for liquid solutions, not solid solutions (e.g., alloys, which use mole fraction or weight percent).
• D: True. Since volume changes with temperature, molarity (moles per liter) varies accordingly.

Conclusion: Correct statements are A and D (option C).

Na₂SO₄ dissociates into Na⁺ and SO₄^2- ions in the electrolysis of aqueous Na₂SO₄. Na⁺ has much lower reduction potential than water and hence Na⁺ ions are not reduced at the cathode. Instead, reduction of water occurs giving out hydrogen gas at the cathode.

Answer: D. Al₂O₃

Explanation:
Al₂O₃ (aluminium oxide) reacts both with acids (to form salts and water) and with bases (to form aluminates), exhibiting amphoteric behavior. Na₂O and CO₂ are basic and acidic oxides respectively, while SO₃ is an acidic

Given,
K = 0.01s^-1
t_1/2 = 0.693/0.01
t_1/2 = 69.3s
[R] = [R]₀/2ⁿ
2ⁿ = [R]₀/[R]
2ⁿ = 2.4/0.3
2ⁿ = 8
n = 3 (number of half-lives)
For 1 half-life t_1/2 = 69.3s
For 3 half-life 3t_1/2 = 3 x 69.3s = 207.9s.

Given,
K = 7.5 x 10^-3 s^-1
K = (2.303/t) x log([R]₀/[R])
t = (2.303/7.5 x 10^-3) x log([100]/[25]) (1/4th part is remaining, so R=25 and R₀  = 100)
t = (2.303/7.5 x 10^-3) x 0.6
t = 38.4s.

The elements located between the s-block and p-block in the long form of the periodic table are known as:

• d-block elements: These elements are characterised by the filling of d-orbitals and include transition metals.
• Actinides: This series consists of elements from actinium (Ac) to lawrencium (Lr) and is found in the f-block.
• Lanthanides: Similar to actinides, lanthanides are also in the f-block, ranging from lanthanum (La) to lutetium (Lu).
• Electropositive elements: Typically, these are metals that readily lose electrons, but this term is more general and does not specifically refer to the d-block.

Among these, the d-block elements are the correct classification for the elements situated between the s and p blocks.

The correct answer is Option B.
 
A solution of potassium chromate, when treated with an excess of dilute nitric acid doesn't oxidize nitric acid as N is already present in its maximum oxidation state (+5). The products formed are Cr2O₇^2- and H₂O.

During racemisation, carbocation intermediate is formed.

Hence option (A) is the answer.

(III) is most reactive as it has most acidic β-H as well as it gives resonance stabilised alkene.Next to (III) is (IV) as it is tertiary. (I) is less reactive than (II) because (I) gives less substituted alkene.

The correct observation about electrolysis is:

a) Electric current is used to drive a non-spontaneous reaction

Detailed Explanation:

1. Correct Option (a):

   • Electrolysis uses an external electric current to force a non-spontaneous redox reaction to occur.

   • In electrolysis, ΔG > 0 (non-spontaneous) and E°cell < 0, requiring energy input from the power source.

   • Example: Decomposition of water (2H₂O → 2H₂ + O₂), which doesn't occur spontaneously.

2. Why Other Options Are Incorrect:

   b) Ecell is positive and ΔG is negative:

   • This describes a galvanic/voltaic cell (spontaneous reaction that generates electricity), not electrolysis.

   • In electrolysis, Ecell is negative (non-spontaneous).

   c) Cations and anions are discharged at the cathode only

   • This is incorrect terminology.

     • Cations (positively charged ions) move to the cathode (where they gain electrons, reduction occurs).

     • Anions (negatively charged ions) move to the anode (where they lose electrons, oxidation occurs).

   • The statement reverses the actual process.

   d) Only overvoltage is responsible that a particular reaction takes place:

   • While overvoltage influences which reaction occurs (e.g., H₂ vs. Na⁺ discharge in aqueous NaCl), it is not the only factor.

   • Other factors include standard reduction potentials and concentration.

Key Concepts:

• Electrolysis requires energy input (electric current) for ΔG > 0 reactions.

• Cathode = Reduction (cations gain electrons).

• Anode = Oxidation (anions lose electrons).

• Overvoltage affects reaction preference but isn't the sole determinant.

Final Answer:

a) Electric current is used to drive a non-spontaneous reaction

o-Toluidine (ortho-toluidine) is an organic compound with the chemical formula CH₃C₆H₄NH₂. It is the most important of the three isomeric toluidines. 

Acrylonitrile is an organic compound with the formula CH₂CHCN. It is a colorless volatile liquid, although commercial samples can be yellow due to impurities.

Ambident groups are those which can attack from both sides. So option a is correct because cyanides is C-N and carbon forms bonds here. Isocyanides are N-C in which nitrogen contains lone pairs which initiates reaction and attaches from nitrogen side.

−NO₂ group is reduced to –NH₂ using H₂/Pd.

The answer are option D
The functional group which is found in amino acid is
Amino acids are organic compounds that contain amine (–NH2) and carboxyl (–COOH) functional groups, along with a side chain (R group) specific to each amino acid.

RNA nucleotides contain ribose sugars while DNA contains deoxyribose and RNA uses predominantly uracil instead of thymine present in DNA.

The correct answer is Option A.
Cellulose is a straight chain polysaccharide composed of D-glucose units which are joined by β-glycosidic linkages.
Hence, cellulose on hydrolysis produces only D-glucose units.