All Free Chemistry MCQs with Answers

• A. Two Double Bonds
• B. Delocalized Pi-Electron Charge
• C. Three Double Bonds
• D. One Sigma Bond

Explanation: Benzene is a cyclic molecule in which all of the ring atoms are sp2-hybridized and contain double bonds.

• A. Benzene
• B. Toluene
• C. Phenol
• D. Diphenylmethane

Explanation: Diphenylmethane is a synthetic compound manufactured by 'The Friedel-Craft Reaction' of benzyl chloride with benzene in the presence of…

• A. Ortho
• B. Meta
• C. Para
• D. None of these

Explanation: Disubstituted benzene rings can be named based on the relative positions of the substituents: the prefix para is used iif they are found…

• A. 154 pm
• B. 120 pm
• C. 134 pm
• D. 139 pm

Explanation: The C−C bond length in benzene is 139 pm. All C−C and C=C bond lengths are the same in benzene.

• A. Alicyclic
• B. Aliphatic compounds
• C. Aromatic compounds
• D. Acyclic compounds

Explanation: Correct option is C. Aromatic compounds, also known as "mono- and polycyclic aromatic hydrocarbons", are organic compounds containing one…

• A. Three triple bonds
• B. Two double bonds
• C. Three double bonds
• D. No multiband

Explanation: Correct option is C. There are 3 double bonds in benzene. Six single bonds between Carbons and Hydrogens, three single bonds between six…

• A. -COOH
• B. -COR
• C. -CN
• D. -OH

Explanation: "-OH" group favors electrophilic attack ortho or para to the substituent while the other group of options doesn't hence the answer is D.

• A. Aldol condensation
• B. Wolf kishner reaction
• C. Wittig reaction
• D. Friedel and craft reaction

Explanation: The reaction in which benzene is reacted with alkyl or acyl halide in the presence of AlCl3 is called Friedel-Craft reaction.

• A. It has low melting and low boiling points
• B. It has high melting and high boiling points
• C. It has low melting and high boiling points
• D. It has a high solubility in polar solvents

Explanation: Arenes are aromatic compounds (contain benzene rings). Hence, they only possess weak Vander Waal's forces as their intermolecular forces…

• A. B
• B. K
• C. Al
• D. Cu

Explanation: s-block comprises 14 elements namely hydrogen (H), lithium (Li), helium (He), sodium (Na), beryllium (Be), potassium (K), magnesium (Mg)…

• A. d-block
• B. s-block
• C. f-block
• D. p-block

Explanation: The s-block in the periodic table of elements occupies the alkali metals and alkaline earth metals, also known as groups 1 and 2.

• A. HF
• B. HCl
• C. HBr
• D. HI

Explanation: HF has greater bond energy than HCl. The bond energy of HF is 568 kJ/moL, while the bond energy of HCl is 431 kJ/moL.

• A. Pressure of mutiple bonds
• B. Nature of hybridization present
• C. Difference in electronegativity between the two bonded atoms
• D. Ionization energies of the two bonded atoms

Explanation: Explanation for this question will be added soon.

• A. Directly proportional
• B. Inversely proportional
• C. Constant
• D. None of these are correct

Explanation: PV=nRT is the overall ideal gas equation derived from Boyle's and Charle's law.

• A. Variable
• B. Constant
• C. Discrete
• D. Decreasing

Explanation: According to Boyle's law, the pressure of a fixed amount of gas varies inversely with its volume, the temperature is maintained…

• A. NH4+
• B. H2O
• C. H+
• D. NH3

Explanation: A conjugate acid, within the Brønsted-Lowry acid-base theory, is a chemical compound formed when an acid donates a proton to a base-in…

• A. NH4+
• B. NH4Cl
• C. HCl fumes
• D. Cl

Explanation: b) NH4Cl:NH4Cl is the correct chemical formula for ammonium chloride. When NH3 gas reacts with HCl gas, it forms ammonium chloride…

• A. It acts both as an acid and a base
• B. It can dissolve both acids and bases
• C. It can give off H+ and OH- ions
• D. In its pure form, it has pH=7
• E. Both A and C

Explanation: Explanation for this question will be added soon.

• A. HCL:H2SO4
• B. HCL:HNO3
• C. HNO3:H2SO4
• D. HNO3:HCL

Explanation: The explanation for this question will be added soon.

• A. Oxidizing
• B. Reducing
• C. Chelating
• D. Chemical

Explanation: The explanation for this question will be added soon.