SSC CGL Chemistry Questions and Answers – Page 2

sed as food preservative to prevent microbial growth. Option B (“Acetic 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 C (“Tartaric 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 (“Citric acid”) 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 Benzoic acid. Sodium benzoate (salt of benzoic acid) is commonly used as food preservative to prevent microbial growth.

Option A (“Enthalpy change only”) 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 (“Entropy change only”) 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 (“Temperature only”) 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 Gibbs free energy change. Gibbs free energy: DeltaG = DeltaH - T x DeltaS.

Option A (“Methanoic 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 B (“Propanoic 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 (“Butanoic acid”) 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 Ethanoic acid. CH3COOH is ethanoic acid (acetic acid).

s to form Na metal. Cl- goes to anode giving Cl2. Option B (“Cl2 gas”) 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 (“NaOH”) 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 (“H2 gas”) 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 Na metal. In molten NaCl electrolysis: Na+ ions go to cathode gaining electrons to form Na metal.

Option B (“NaCl”) 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 (“NaOH”) 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 (“Na2SO4”) 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 Na2CO3. Na2CO3 (soda ash) is used along with SiO2 and CaO in the manufacture of glass.

Option B (“Silicon nitride”) 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 (“Silicon dioxide”) 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 (“Calcium carbide”) 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 Silicon carbide. Carborundum is silicon carbide (SiC).

Option B (“Acidic KMnO4”) 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 (“K2Cr2O7”) 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 (“Ozone”) 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 Alkaline KMnO4. Baeyer's reagent is alkaline KMnO4 (cold dilute).

largest atomic radius among alkali metals. Atomic radius increases down a group. Cs is at the bottom of Group 1 so has largest atomic radius among alkali metals.

yl chloride (CH2=CHCl) by Markovnikov's addition. Option A (“CH3CHO”) 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 (“CHCl3”) 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 (“CH3Cl”) 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 CH2=CHCl. Acetylene + HCl (with HgCl2 catalyst) gives vinyl chloride (CH2=CHCl) by Markovnikov's addition.

It depends on both Ka of weak acid and Kw of water. Option A (“Ka only”) 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 (“Kw only”) 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 (“pH of solution”) 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 Both Ka and Kw. Degree of hydrolysis h = sqrt(Kw/Ka x Cm).