Bonding Review Regents Chemistry Multiple Choice Question 1

Bonding Review Regents Chemistry

Multiple Choice

Question: 1. Which sequence of Group 18 elements demonstrates a gradual decrease in the strength of the Van der Waals forces? A) Ar, Kr, Ne, Xe B) Xe, Kr, Ar, Ne C) Kr, Xe, Ar, Ne D) Ne, Ar, Kr, Xe

Answer: Correct Answer: Option B - Xe, Kr, Ar, Ne The van der Waals force (or van der Waals interaction) is the attractive or repulsive force between molecules (or between parts of the same molecule) other than those due to covalent bonds or to the electrostatic interaction of ions with one another or with neutral molecules. These forces decrease as the molecule gets smaller and increase as the molecule increases. Therefore the Van der Waals forces would also be decreasing. Xe, Kr, Ar, Ne are in the order of decreasing molecule size. Hence, only option B is the correct answer and the other 3 options are incorrect.

Question: 2. Which combination of atoms can form a polar covalent bond? A) N and N B) H and H C) Na and Br D) H and Br

Answer: Correct Answer: Option D - H and Br The electronegativity difference between H (2. 1) and Br (3. 0) is 0. 9. If the difference is less than 1. 7 (but not zero, usually more than 0. 4), a polar covalent bond is formed. A nonpolar covalent bond is formed when the difference is close to zero (usually up to 0. 4). If the difference is more than 1. 7, an ionic bond is formed. Hence, options A, B and C are incorrect.

Question: 3. As a bond between a hydrogen atom and a sulfur atom is formed, electrons are: A) Shared to form a covalent bond B) Shared to form an ionic bond C) Transferred to form an ionic bond D) Transferred to form a covalent bond

Answer: Correct Answer: Option A - Shared to form a covalent bond

Question: 4. Which element has an atom with the greatest attraction for electrons in a chemical bond? A) Arsenic B) Nitrogen C) Bismuth D) Phosphorus

Answer: Correct Answer: Option B – Nitrogen has an electronegativity of 3. 04 Pauling Units Incorrect Options Arsenic has an electronegativity of 2. 18 Pauling Units Bismuth has an electronegativity of 2. 02 Pauling Units Phosphorus has an electronegativity of 2. 19 Pauling Units

Question: 5. Which formula represents a polar molecule? A) Br 2 B) CH 4 C) CO 2 D) NH 3

Answer: Correct Answer: Option D - NH 3

Question: 6. What can be concluded if an ion of an element is smaller than an atom of the same element? A) The ion is negatively charged because it has fewer electrons than the atom. B) The ion is negatively charged because it has more electrons than the atom. C) The ion is positively charged because it has fewer electrons than the atom. D) The ion is positively charged because it has more electrons than the atom.

Answer: Correct Answer: Option C - The ion is positively charged because it has fewer electrons than the atom.

Question: 7. Which compound contains both ionic and covalent bonds? A) Sodium nitrate B) Ammonia (NH 3) C) Methane (CH 4) D) Potassium chloride

Answer: Correct Answer: Option A - Sodium nitrate

Question: 8. Which bond has the greatest ionic character? A) H---N B) H---F C) H---Cl D) H---O

Answer: Correct Answer: Option B - H---F

Question: 9. A barium atom attains a stable electron configuration when it bonds with: A) 1 chlorine atom B) 1 sodium atom C) 2 chlorine atoms D) 2 sodium atoms

Answer: Correct Answer: Option C - 2 chlorine atoms

Question: 10. A solid substance is an excellent conductor of electricity. The chemical bonds in this substance are most likely A) Ionic, because the valence electrons are shared between atoms B) Ionic, because the valence electrons are mobile C) Metallic, because the valence electrons are stationary D) Metallic, because the valence electrons are mobile

Answer: Correct Answer: Option D - Metallic, because the valence electrons are mobile

Question: 11. Which statement describes what occurs as two atoms of bromine combine to become a molecule of bromine? A) Energy is absorbed as a bond is formed. B) Energy is absorbed as a bond is broken. C) Energy is released as a bond is formed. D) Energy is released as a bond is broken.

Answer: Correct Answer: Option C - Energy is released as a bond is formed.

Question: 12. An oxygen molecule contains a double bond because the two atoms of oxygen share a total of A) 1 electron B) 3 electrons C) 2 electrons D) 4 electrons

Answer: Correct Answer: Option D - 4 electrons

Question: 13. A substance whose water solution will readily conduct electricity is: A) C 2 H 5 OH B) Na. OH C) CCl 4 D) C 6 H 12 O 6

Answer: Correct Answer: Option B - Na. OH

Question: 14. To become a calcium ion a calcium atom must: A) Gain 2 ions B) Gain 2 protons C) Lose 2 neutrons D) Lose 2 electrons

Answer: Correct Answer: Option D - Lose 2 electrons

Question: 15. The formula Cl 2 represents one: A) Atom B) Ion C) Molecule D) Radical

Answer: Correct answer: Option C - Molecule

Question: 16. Which formula represents a molecular substance? A) Ca. O B) CO C) Li 2 O D) Al 2 O 3

Answer: Correct Answer Number: B Explanation: Use Ref. Table S to determine the electronegativity difference of each of the choices. The difference between C (2. 6) and O (3. 4) is 0. 9 or in the range of covalent bonding (covalent bonds have electronegativity differences of less than 1. 7). The other three compounds have differences in the ionic bond range or over 1. 7.

Short Answer

Question: (taken from June 2010 Regents exam) 17. What is the total number of electron pairs shared between the carbon atom and one of the oxygen atoms in a carbon dioxide molecule? .

Answer: two electron pairs (because carbon dioxide is double bonded)

Question: (taken from June 2010 Regents exam) 18. Explain, in terms of subatomic particles, why the radius of a chloride ion is larger than the radius of a chlorine atom.

Answer: A Cl− ion has 18 electrons and 17 protons, so there is less attraction by the nucleus for the electron shells, allowing the electron shells to expand. The radius of Cl− is larger because the nucleus can’t hold 18 electrons as close as it can hold 17 electrons.

Question: (taken from June 2010 Regents exam) 19. Explain, in terms of valence electrons, why the bonding in magnesium oxide, Mg. O, is similar to the bonding in barium chloride, Ba. Cl 2

Answer: The bonding in each compound involves a transfer of valence electrons from the metal to the nonmetal. Both metals lose all of their valence electrons.