All Free Chemistry MCQs with Answers
Every Chemistry question in the bank, across all chapters, each with the correct answer and a written explanation. Free and unlimited, with no account needed.
13,720 questions · page 559 of 686
- A. 4 hydrogen bonds
- B. 3 hydrogen bonds
- C. 2 hydrogen bonds
- D. 1 hydrogen bond
Explanation: Each water (H₂O) molecule can form four hydrogen bonds in total:2 hydrogen atoms → can each form 1 hydrogen bond (as donors)2 lone pairs…
Correct answer: 4 hydrogen bonds11162. Select amongst the following which is not a correct statement for the element it is referring to:
- A. Nitrogen is a poor conductor of heat and electricity.
- B. Nitrogen forms not only acidic oxides.
- C. Nitrogen has the greatest tendency to attract electrons.
- D. The compounds formed by nitrogen are predominantly covalent.
Explanation: The correct answer is Option C: Nitrogen has the greatest tendency to attract electrons.
Correct answer: Nitrogen has the greatest tendency to attract electrons.- A. HCl
- B. HBr
- C. HI
- D. HF
Explanation: The ionic character of a bond is largely determined by the difference in electronegativity between the two bonded atoms.
Correct answer: HF- A. Unit molecule
- B. Unit cell
- C. Unit crystal
- D. All of these options are correct
Explanation: A 'unit cell' is the smallest group of atoms that has the overall symmetry of a crystal, and from which the entire lattice can be built up…
Correct answer: Unit cell- A. Smaller.
- B. Greater
- C. None of these
- D. Lower
Explanation: The greater the amount of negative charge on an atom, the size of the ion will also be greater.
Correct answer: Greater- A. Electron pool theory
- B. Valence bond theory
- C. Band Theory
- D. None of these options are correct
Explanation: The molecular theory for metals is called band theory. Band theory is a quantum mechanical model that explains the behavior of electrons…
Correct answer: Band Theory- A. Always form Pi(π) bond
- B. Always form Sigma(σ) bond
- C. Neither form σ nor π bond
- D. Form more reactive and more unstable π bond
Explanation: Unhybridized orbitals can only form π bonds upon sideways or parallel overlap and cannot form sigma bonds.
Correct answer: Always form Pi(π) bond- A. F→ F
- B. Cl→ Cl
- C. O→ O
- D. H2→2H
Explanation: The amount of energy released when an electron is added to an atom is termed as electron affinity.
Correct answer: H2→2H- A. Intramolecular hydrogen bonds
- B. Disulfide bonds
- C. A rippled effect
- D. Hydrophobic interactions
Explanation: A. a-helix and beta pleated sheets have hydrogen bonding so Option A is correct.B.
Correct answer: Intramolecular hydrogen bonds- A. CH4
- B. PCl5
- C. NH4+
- D. PCl3
Explanation: The correct answer is PCl3. In PCl3, the central phosphorus atom forms three single bonds with chlorine atoms and has one lone pair of…
Correct answer: PCl3- A. Angular
- B. Trigonal pyramidal
- C. Tetrahedral
- D. None
Explanation: An angular geometry has 2 electron groups around the central atom, and an AB4 type molecule has 4 electron groups around the central atom.
Correct answer: Angular- A. Ionic bonds are formed between atoms of elements with very different electronegativities, while covalent bonds are formed between atoms of elements with similar electronegativities.
- B. Covalent compounds have low melting and boiling points, whereas ionic compounds have high melting and boiling points.
- C. Ionic bonds are directional, while covalent bonds are non-directional.
- D. Covalent compounds are poor conductors of electricity, whereas ionic compounds are good conductors of electricity when molten or in solution.
Explanation: Ionic bonds are formed between atoms of different elements with very different electronegativities.
Correct answer: Ionic bonds are directional, while covalent bonds are non-directional.- A. Inter-titan distance R
- B. Interionic distance R
- C. Inter-cationic distance R+
- D. Inter-anionic distance R-
Explanation: Option B is correct.The sum of cationic and anionic radius in a crystal lattice is equal to the interionic distance.
Correct answer: Interionic distance R- A. 2, 8, 8, 2
- B. 2, 8, 8
- C. 2, 8, 1
- D. 2, 888
Explanation: The correct answer is B) 288. Potassium (K) becomes K+ by losing one electron and achieving an electronic configuration of (2, 8, 8).
Correct answer: 2, 8, 8- A. J mol-1
- B. kJ mol-1
- C. kJ atom-1
- D. J atom-1
Explanation: The correct answer is B) kJ mol^-1. The unit of electron affinity is kilojoules per mole (kJ mol^-1), which represents the energy change…
Correct answer: kJ mol-1- A. All are present in the solid state
- B. All conduct electricity in the molten state
- C. All show polymorphism and isomerism
- D. All have non-directional and non-rigid bonds
Explanation: The correct answer is Option C: All show polymorphism and isomerism.Ionic compounds typically do not exhibit isomerism because their…
Correct answer: All show polymorphism and isomerism- A. Pairing of electrons
- B. Shifts of atoms
- C. Sharing of electrons
- D. None of the above
Explanation: The HF bond is formed by the sharing of the electrons, resulting in a strong bond that is highly polar.
Correct answer: Sharing of electrons- A. SO3
- B. NH3
- C. CO2
- D. NO
Explanation: The reason why SO3 has a perfect triangular structure is because the sulfur atom has 6 valence electrons, and it shares 2 electrons with…
Correct answer: SO3- A. IA and IIA
- B. IB and VIIB
- C. IA, llA and VII A
- D. IA and IB
Explanation: In ionic compounds, one element donates electrons (typically a metal or an element with low electronegativity), becoming a positively…
Correct answer: IA, llA and VII A- A. 0
- B. 1
- C. 3
- D. 4
Explanation: Ammonia (NH3) has one unpaired electron. Each hydrogen (H) atom contributes one electron to form a covalent bond with the central nitrogen…
Correct answer: 1