SSC CGL Chemistry Questions and Answers – Page 3

crystals are green in colour due to Fe2+ ions. Option A (“White”) is incorrect because it does not satisfy the chemical formula, reaction, periodic trend, numerical relation, oxidation state or definition required by the question. Option B (“Blue”) is incorrect because it does not satisfy the chemical formula, reaction, periodic trend, numerical relation, oxidation state or definition required by the question. Option D (“Red”) is incorrect because it does not satisfy the chemical formula, reaction, periodic trend, numerical relation, oxidation state or definition required by the question. The answer field, correct index and explanation therefore all identify Green. Ferrous sulphate (FeSO4.7H2O) crystals are green in colour due to Fe2+ ions.

Option A (“Nitrobenzene”) is incorrect because it does not satisfy the chemical formula, reaction, periodic trend, numerical relation, oxidation state or definition required by the question. Option C (“Benzoic acid”) is incorrect because it does not satisfy the chemical formula, reaction, periodic trend, numerical relation, oxidation state or definition required by the question. Option D (“Benzaldehyde”) is incorrect because it does not satisfy the chemical formula, reaction, periodic trend, numerical relation, oxidation state or definition required by the question. The answer field, correct index and explanation therefore all identify Chlorobenzene. Chlorobenzene: Cl is ortho-para director due to lone pair donation despite being electron-withdrawing by induction.

(not diamagnetic) due to presence of unpaired d-electrons. Option A (“Variable oxidation states”) is incorrect because it does not satisfy the chemical formula, reaction, periodic trend, numerical relation, oxidation state or definition required by the question. Option B (“Formation of colored compounds”) is incorrect because it does not satisfy the chemical formula, reaction, periodic trend, numerical relation, oxidation state or definition required by the question. Option D (“Catalytic activity”) is incorrect because it does not satisfy the chemical formula, reaction, periodic trend, numerical relation, oxidation state or definition required by the question. The answer field, correct index and explanation therefore all identify Diamagnetic nature. Most transition metals are paramagnetic (not diamagnetic) due to presence of unpaired d-electrons.

Option A (“NO”) is incorrect because it does not satisfy the chemical formula, reaction, periodic trend, numerical relation, oxidation state or definition required by the question. Option B (“NO2”) is incorrect because it does not satisfy the chemical formula, reaction, periodic trend, numerical relation, oxidation state or definition required by the question. Option D (“N2O3”) is incorrect because it does not satisfy the chemical formula, reaction, periodic trend, numerical relation, oxidation state or definition required by the question. Identify the governing formula, definition or reaction and apply it consistently. The answer field, correct index and explanation therefore all identify N2O. Laughing gas is nitrous oxide with formula N2O.

Mn has oxidation state +7. Option A (“+5”) is incorrect because it does not satisfy the chemical formula, reaction, periodic trend, numerical relation, oxidation state or definition required by the question. Option B (“+6”) is incorrect because it does not satisfy the chemical formula, reaction, periodic trend, numerical relation, oxidation state or definition required by the question. Option D (“+4”) is incorrect because it does not satisfy the chemical formula, reaction, periodic trend, numerical relation, oxidation state or definition required by the question.

(van der Waals) so they have the lowest melting points. Option A (“Ionic solid”) is incorrect because it does not satisfy the chemical formula, reaction, periodic trend, numerical relation, oxidation state or definition required by the question. Option B (“Covalent solid”) is incorrect because it does not satisfy the chemical formula, reaction, periodic trend, numerical relation, oxidation state or definition required by the question. Option C (“Metallic solid”) is incorrect because it does not satisfy the chemical formula, reaction, periodic trend, numerical relation, oxidation state or definition required by the question. The answer field, correct index and explanation therefore all identify Molecular solid. Molecular solids have weakest intermolecular forces (van der Waals) so they have the lowest melting points.

rmines the energy level (shell) and the size of the atomic orbital. Option A (“Shape of orbital”) is incorrect because it does not satisfy the chemical formula, reaction, periodic trend, numerical relation, oxidation state or definition required by the question. Option B (“Orientation of orbital”) is incorrect because it does not satisfy the chemical formula, reaction, periodic trend, numerical relation, oxidation state or definition required by the question. Option D (“Number of electrons in orbital”) is incorrect because it does not satisfy the chemical formula, reaction, periodic trend, numerical relation, oxidation state or definition required by the question. Identify the governing formula, definition or reaction and apply it consistently. The answer field, correct index and explanation therefore all identify Energy and size of orbital. Principal quantum number n determines the energy level (shell) and the size of the atomic orbital.

Electrophile Br+ attacks aromatic ring. Option B (“Benzene + HBr to bromobenzene”) is incorrect because it does not satisfy the chemical formula, reaction, periodic trend, numerical relation, oxidation state or definition required by the question. Option C (“Benzene + Br2 (UV light) to bromobenzene”) is incorrect because it does not satisfy the chemical formula, reaction, periodic trend, numerical relation, oxidation state or definition required by the question. Option D (“Benzene + NaBr to bromobenzene”) is incorrect because it does not satisfy the chemical formula, reaction, periodic trend, numerical relation, oxidation state or definition required by the question. The answer field, correct index and explanation therefore all identify Benzene + Br2 to bromobenzene. Benzene + Br2 with Lewis acid catalyst (FeBr3) gives EAS.

Wave number = 15233 cm^-1. Option B (“20565 cm^-1”) is incorrect because it does not satisfy the chemical formula, reaction, periodic trend, numerical relation, oxidation state or definition required by the question. Option C (“27419 cm^-1”) is incorrect because it does not satisfy the chemical formula, reaction, periodic trend, numerical relation, oxidation state or definition required by the question. Option D (“5331 cm^-1”) is incorrect because it does not satisfy the chemical formula, reaction, periodic trend, numerical relation, oxidation state or definition required by the question. The answer field, correct index and explanation therefore all identify 15233 cm^-1. Balmer series n1=2 to n=3 transition.

Option A (“Addition of carbon black”) is incorrect because it does not satisfy the chemical formula, reaction, periodic trend, numerical relation, oxidation state or definition required by the question. Option C (“Hydrogenation”) is incorrect because it does not satisfy the chemical formula, reaction, periodic trend, numerical relation, oxidation state or definition required by the question. Option D (“Polymerization”) is incorrect because it does not satisfy the chemical formula, reaction, periodic trend, numerical relation, oxidation state or definition required by the question. The answer field, correct index and explanation therefore all identify Cross-linking by sulphur. Vulcanization involves heating rubber with sulfur. Sulfur creates cross-links between polymer chains making it harder and more elastic.