Shapes of Molecules MCQs PDF

1. What is the shape of methane (CH₄)? a) Linear b) Bent c) Tetrahedral d) Trigonal planar Answer: c) Tetrahedral Explanation: Methane has four bonding pairs of electrons which repel each other equally, forming a tetrahedral shape with bond angles of 109.5°. 2. Which molecule has...

1. What is the shape of methane (CH₄)? a) Linear b) Bent c) Tetrahedral d) Trigonal planar Answer: c) Tetrahedral Explanation: Methane has four bonding pairs of electrons which repel each other equally, forming a tetrahedral shape with bond angles of 109.5°. 2. Which molecule has a trigonal planar shape? a) CCl₄ b) SO₂ c) BF₃ d) NH₃ Answer: c) BF₃ Explanation: BF₃ has three bonding pairs and no lone pairs on the central atom, arranging in a trigonal planar shape with bond angles of 120°. 3. What is the bond angle in a molecule with a linear shape? a) 109.5° b) 90° c) 120° d) 180° Answer: d) 180° Explanation: In a linear molecular geometry, the bond angle between atoms is 180°【. 4. Which molecule adopts a bent shape? a) CO₂ b) H₂O c) CH₄ d) BF₃ Answer: b) H₂O Explanation: H₂O has two bonding pairs and two lone pairs of electrons, causing a bent shape with a bond angle of approximately 104.5°. 5. How many bonding pairs and lone pairs are in a trigonal pyramidal molecule like NH₃? a) 3 bonding pairs, 1 lone pair b) 3 bonding pairs, no lone pairs c) 4 bonding pairs, no lone pairs d) 2 bonding pairs, 2 lone pairs Answer: a) 3 bonding pairs, 1 lone pair Explanation: NH₃ has three bonding pairs and one lone pair of electrons, leading to a trigonal pyramidal shape with bond angles of 107°. 6. What is the bond angle in a tetrahedral molecule? a) 120° b) 104.5° c) 109.5° d) 90° Answer: c) 109.5° Explanation: In a tetrahedral molecular geometry, the bond angle is 109.5° due to the repulsion between four bonding pairs of electrons.  7. Which shape does carbon dioxide (CO₂) present? a) Bent b) Tetrahedral c) Linear d) Trigonal pyramidal Answer: c) Linear Explanation: CO₂ has two regions of electron density around the central carbon atom causing repulsion that places the oxygen atoms in a linear arrangement with a 180° bond angle. 8. What is the molecular shape of ammonia (NH₃)? a) Trigonal planar b) Tetrahedral c) Trigonal pyramidal d) Bent Answer: c) Trigonal pyramidal Explanation: Ammonia has three bonding pairs and one lone pair, creating a trigonal pyramidal shape with bond angles of 107°. 9. Identify the bond angle in a molecule with trigonal planar shape like BF₃. a) 109.5° b) 180° c) 90° d) 120° Answer: d) 120° Explanation: In a trigonal planar molecular geometry, the bond angles between the atoms are 120° due to equal repulsion between three bonding pairs. 10. What shape does BeCl₂ adopt? a) Tetrahedral b) Trigonal planar c) Linear d) Bent Answer: c) Linear Explanation: BeCl₂ has two regions of electron density around the central beryllium atom, leading to a linear shape with bond angles of 180°. 11. Deducing the shape of a molecule involves considering what factor? a) Atomic masses b) Number of valence electrons c) Electronegativity values d) Arrangement of electron pairs Answer: d) Arrangement of electron pairs Explanation: The VSEPR theory states that the shape of a molecule is determined by the arrangement of electron pairs around the central atom to minimise repulsion. 12. Which molecule has bond angles of 90°? a) Carbon tetrachloride (CCl₄) b) Ammonia (NH₃) c) Phosphorus pentachloride (PCl₅) d) Sulfur hexa uoride (SF₆) Answer: d) Sulfur hexa uoride (SF₆) Explanation: SF₆ has a shape with octahedral geometry where the bond angles between the uorine atoms are 90°. fl fl fl  13. Which feature of H₂O causes it to have bent shape with bond angles of 104.5°? a) Two bonding pairs repelling each other b) Two lone pairs repelling each other c) One bonding pair and one lone pair repelling each other d) Repelling by four bonding pairs Answer: a) Two bonding pairs repelling each other Explanation: H₂O has two bonding pairs and two lone pairs that cause the bond angle to be reduced from the expected tetrahedral angle to 104.5° due to repulsion. 14. Which molecular shape is characterised by ve electron pairs around the central atom like in PCl₅? a) Tetrahedral b) Square planar c) Trigonal bipyramidal d) Bent Answer: c) Trigonal bipyramidal Explanation: PCl₅ has ve bonding pairs around the central atom which arrange themselves in trigonal bipyramidal geometry with bond angles of 90° and 120°. 15. What shape does a molecule like SiCl₄ have and what are the bond angles? a) Linear, 180° b) Tetrahedral, 109.5° c) Trigonal planar, 120° d) Bent, 104.5° Answer: b) Tetrahedral, 109.5° Explanation: SiCl₄ has four bonding pairs around the silicon atom which arrange in a tetrahedral shape with bond angles of 109.5°. 16. Which molecule has a square planar shape? a) SF₆ b) ICl₄⁻ c) NH₃ d) SiO₂ Answer: b) ICl₄⁻ Explanation: ICl₄⁻ has four bonding pairs and two lone pairs around the central iodine atom, resulting in a square planar shape with bond angles of 90°. 17. Which shape does NH₄⁺ ion adopt? a) Linear b) Tetrahedral c) Bent d) Trigonal planar Answer: b) Tetrahedral Explanation: NH₄⁺ has four bonding pairs of electrons arranging themselves into a tetrahedral shape with bond angles of 109.5°. 18. How does the presence of lone pairs a ect the bond angles in molecules like NH₃? a) Increases bond angles b) Decreases bond angles c) No e ect on bond angles d) Depends on the element Answer: b) Decreases bond angles Explanation: Lone pairs repel bonding pairs more strongly, thus ff fi ff fi