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 561 of 686
- A. Merge
- B. Integrate
- C. Overlap
- D. Separate
Explanation: The correct answer is C) Overlap. According to Valence Bond Theory, the essential condition for chemical bonding is that the orbitals of…
Correct answer: Overlap- A. Decreases
- B. Increases
- C. Remains same
- D. First increases then decreases
Explanation: In a period of the periodic table, the number of inner electron shells remains the same, while the nuclear charge (the number of protons…
Correct answer: Remains same- A. Electron is added to a gaseous atom.
- B. A covalent bond in a molecule is broken.
- C. An electron is removed from a gaseous atom.
- D. A covalent bond is formed between atoms.
Explanation: The correct answer is that electron affinity refers to the energy released when an electron is added to a gaseous atom, resulting in the…
Correct answer: Electron is added to a gaseous atom.- A. Increase.
- B. Remain the same.
- C. Decrease.
- D. First increase, then decrease.
Explanation: Along the period, the number of shells remain same and the attraction of nucleus towards outermost electrons increase with increase in…
Correct answer: Decrease.- A. Ionization energy
- B. Electropositivity
- C. Electronegativity
- D. Electron affinity
Explanation: Ionization energy: The amount of energy required to remove the most loosly bonded electron,valance electron to form a cation.
Correct answer: Ionization energy- A. H2
- B. CI2
- C. N2
- D. All of these
Explanation: Among the molecules H2 (hydrogen gas), Cl2 (chlorine gas), and N2 (nitrogen gas), all of them contain non polar covalent bonds.
Correct answer: All of these- A. Boron
- B. Nitrogen
- C. Carbon
- D. Oxygen
Explanation: Nitrogen having a half-filled 2p orbital will have no electron pairs in the valence shell, so there will be no repulsion.
Correct answer: Nitrogen- A. PH3, NH3
- B. BF3, PCI3
- C. H2S, CO2
- D. So2, CO2
Explanation: NH3 (Ammonia) has a pyramidal shape, with the nitrogen atom in the center and three hydrogen atoms surrounding it.
Correct answer: PH3, NH311209. Which of the following best describes the shape and polarity of the carbon disulphide molecule?
- A. Bent and polar
- B. Pyramidal and polar
- C. Linear and non-polar
- D. Bent and non-polar
Explanation: The carbon disulfide (CS2) molecule has a linear shape and is nonpolar.
Correct answer: Linear and non-polar- A. Polar covalent bond.
- B. Non-polar covalent bond.
- C. Pie bond.
- D. Co-ordinate covalent bond.
Explanation: In 'H-F' bond electronegativity difference is '1.9'. they show polar covalent bond.
Correct answer: Polar covalent bond.- A. Sigma Bond.
- B. Pie-Bond.
- C. Hydrogen Bond.
- D. Metallic Bond.
Explanation: When the two partially filled atomic orbitals overlap in such a way that the probability of finding electron is maximum around the line…
Correct answer: Sigma Bond.- A. Electron is added to gaseous atom.
- B. Covalent bond is of molecule is broken.
- C. Electron is removed from gaseous atom.
- D. Covalent bond is formed between the atoms.
Explanation: The electron affinity of an atom is the energy released when an electron adds to an empty or partially filled orbital of an isolated…
Correct answer: Electron is added to gaseous atom.- A. increase.
- B. remain same.
- C. decrease
- D. first increase, then decrease.
Explanation: Along the period, the number of shells remain same and the attraction of nucleus towards outermost electrons increase with increase in…
Correct answer: decrease- A. Parallel to sp2
- B. In the same plane
- C. Perpendicular to sp2 orbitals
- D. Out of plane
Explanation: In sp2 hybridization, the unhybridized "p" orbital is perpendicular to the plane formed by the three sp2 hybrid orbitals.
Correct answer: Perpendicular to sp2 orbitals- A. PCI5
- B. SF6
- C. NH3
- D. HN=NH
Explanation: NH3 has sp3 hybridization. In ammonia, the central nitrogen (N) atom forms three sigma bonds with three hydrogen atoms.
Correct answer: NH3- A. NH3
- B. NCI3
- C. NF3
- D. NBr3
Explanation: NH3 has a bond angle of approximately 107 degrees. The central nitrogen (N) atom is bonded to three hydrogen (H) atoms, and the lone pair…
Correct answer: NH3- A. NH 4Cl
- B. NaCl
- C. HCl
- D. AlCl3
Explanation: NH4Cl (Ammonium Chloride) is the one that contains all three types of chemical bonds: covalent, ionic, and potential hydrogen bonding.
Correct answer: NH 4Cl11218. In which sequence are the molecules quoted in order of increasing bond angle with in the molecule:
- A. H2O, SF6, BF3
- B. NH3, CH4, H2O
- C. H2O, CO2, BF3
- D. H2O, H2O, BF3
Explanation: Ammonia has trigonal pyramidal shape, methane has tetrahedral geometry while H2O show linear geometry.
Correct answer: NH3, CH4, H2O- A. I A
- B. II A, V A
- C. VA, VII A
- D. V A, VIII A
Explanation: The elements of group IIA and VA show abnormally low values in every period of the periodic table.
Correct answer: II A, V A- A. F, CI
- B. CI, Br
- C. F, Br
- D. Br, I
Explanation: Cl has electron affinity value -349kJ/mol and Br has electron affinity value -324kJ/mol which are the closest among given options.
Correct answer: F, Br