All Free Chemistry MCQs with Answers

• A. Barometric method is more accurate than Manometric method.
• B. Manometric method is more accurate than Barometric method.
• C. Both are equally accurate and applicable.
• D. Both methods are in use but are not reliable.

Explanation: Barometers are more limited in design and function than manometers, hence, manometers can calculate other pressures along with atmospheric…

• A. Absence of hydrogen bonding
• B. High latent heat of vaporization
• C. Freely moving molecules
• D. Statement is incorrect

Explanation: Steam has more warmth and vitality than water. Due to its dormant warmth of vaporization, it will produce more burn than boiling water.

• A. Carbon tetrachloride
• B. Ethyl alcohol
• C. Benzene
• D. Acetic acid

Explanation: Option A (Carbon tetrachloride) is correct. It has the lowest boiling point because it is a nonpolar molecule with weak intermolecular…

• A. Thermo-chemistry
• B. Thermodynamics
• C. Electro chemistry
• D. Chemical kinetics

Explanation: Thermochemistry is the study of the heat energy which is associated with chemical reactions and/or phase changes such as melting and…

• A. Exothermic
• B. Endothermic
• C. Reversible
• D. None of above

Explanation: Exothermic: An exothermic reaction is a chemical reaction that releases energy in the form of heat.

• A. Nitrous oxide
• B. Carbon oxide
• C. Arsenic oxide
• D. Nitrogen oxide

Explanation: In the contact process, the catalyst used is typically a combination of vanadium(V) oxide (V2O5) or platinum (Pt) supported on a substrate…

• A. The reaction is exothermic and the heat generated speeds up the reaction
• B. The hydrogen liberated during the reaction acts as a catalyst
• C. The protective oxide layer of the aluminum dissolves and the meal surface is exposed to the reactant
• D. Sodium aluminate is highly soluble; therefore, it helps the reaction move in the forward direction

Explanation: Aluminium has a protective coat, due to which it initially reacts slowly.

• A. q = △E + W
• B. △E = q - W
• C. q = △E - P△V
• D. All of the above

Explanation: The first Law of Thermodynamics is represented by the formula: ΔE = q − W.

• A. Primary amines
• B. Secondary amines
• C. Tertiary amines
• D. All of these

Explanation: Only primary amines give the carbylamine test. Hoffmann's carbylamine test/ Isocyanide test:Aliphatic or aromatic primary amines on…

• A. They are highly reactive compounds.
• B. They are very stable compounds and can be isolated easily.
• C. They have synthetic importance.
• D. They are represented by the general formula RMgX.

Explanation: The correct answer is They are very stable compounds and can be isolated easily.

• A. Carbocation
• B. Oxonium ion
• C. Carbanion
• D. Oxalate ion

Explanation: When ethoxy ethane is treated with concentrated H2SO4, the oxygen atom in ethoxy ethane donates a lone pair to the hydrogen ion from the…

• A. CH3-CH2-C-Br
• B. CH3-C-O-C- CH3
• C. CH3- CH2-C-NH2
• D. None of the above

Explanation: All of the above compounds can be hydrolyzed by water to split into 2 smaller molecules so option D is correct

• A. R-S-R
• B. R-S-H
• C. R-O-R
• D. R-O-H

Explanation: Mercaptans are organosulfur molecules composed of carbon, hydrogen, and sulfur.

• A. Methyl amine
• B. Dimethyl amine
• C. Methyl propyl amine
• D. Butyl amine

Explanation: The greater the basicity of amines the higher its reactivity. Order of basicity if the −R group is −CH3 group:Secondary amine > primary…

• A. Br+
• B. AlCl3
• C. NH4
• D. NO3+

Explanation: Ammonium ion (NH4+) is not an electrophile. It is a positively charged species, but it does not have an electron-deficient center that can…

• A. Propyne
• B. Propanone
• C. Propanal
• D. Propene

Explanation: Nail polish removers are mainly composed of propanone, which is more commonly known as acetone.

• A. The acidulation of phosphate rock
• B. The alkylation of phosphate rock
• C. The alcoholation of phosphate rock
• D. The alkali addition of phosphate rock

Explanation: The correct answer is A: "The acidulation of phosphate rock." Superphosphate is a fertilizer that is commonly used to provide plants with…

• A. Burning of waste material in pits
• B. Converting the solid waste into useful products by thermal treatment
• C. Energy recovery from organic matter prior to its final disposal
• D. Size reduction and compaction by thermal process

Explanation: The primary function of thermal treatment is to convert the waste to a stable and usable end product. Therefore the answer will be B.

• A. Ammonium nitrate
• B. Triple phosphate
• C. Urea
• D. Nitro phosphate

Explanation: The correct answer is Triple phosphate. It is a phosphate fertilizer, primarily providing phosphorus rather than nitrogen.

• A. 10-30%
• B. 50-90%
• C. 50-75%
• D. 60-75%

Explanation: Biogas is predominantly composed of methane (CH4) and carbon dioxide (CO2).