January 2010 Chemistry Regents #11-20
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Questions | Answer | Link | Explanations |
| 11 Which formula represents a nonpolar molecule? (1) HCl (3) NH3 (2) H2O (4) CH4 | 4 | Link | draw them, the symmetrical one is nonpolar |
| 12 Which symbol represents an atom in the ground state with the most stable valence electron configuration? (1) B (3) Li (2) O (4) Ne | 4 | Link | Group 18 is stable |
| 13 Which element has an atom with the greatest tendency to attract electrons in a chemical bond? (1) carbon (3) silicon (2) chlorine (4) sulfur | 2 | Link | Definition of Electronegativity, Table S |
| 14 The nitrogen atoms in a molecule of N2 share a total of (1) one pair of electrons (2) one pair of protons (3) three pairs of electrons (4) three pairs of protons | 3 | Link | Nitrogen triple bonds |
| 15 An ionic compound is formed when there is a reaction between the elements (1) strontium and chlorine (2) hydrogen and chlorine (3) nitrogen and oxygen (4) sulfur and oxygen | 1 | Link | metal and nonmetal |
| 16 Which compound has both ionic and covalent bonding? (1) CaCO3 (3) CH3OH (2) CH2Cl2 (4) C6H12O6 | 1 | Link | Look for 3 elements and 1 must be a metal |
| 17 The liquids hexane and water are placed in a test tube. The test tube is stoppered, shaken, and placed in a test tube rack. The liquids separate into two distinct layers because hexane and water have different (1) formula masses (2) molecular polarities (3) pH values (4) specific heats | 2 | Link | like dissolves like, water is polar and hexane is not |
| 18 Which statement describes the particles of an ideal gas based on the kinetic molecular theory? (1) The gas particles are relatively far apart and have negligible volume. (2) The gas particles are in constant, nonlinear motion. (3) The gas particles have attractive forces between them. (4) The gas particles have collisions without transferring energy. | 1 | Link | straight line motion, no attractions allowed |
| 19 Under which conditions of temperature and pressure would a 1-liter sample of a real gas behave most like an ideal gas? (1) 100 K and 0.1 atm (2) 100 K and 10 atm (3) 500 K and 0.1 atm (4) 500 K and 10 atm | 3 | Link | ideal gas= ideal vacation high temps and low pressures |
| 20 Which type of energy is associated with the random motion of the particles in a sample of gas? (1) chemical energy (2) electromagnetic energy (3) nuclear energy (4) thermal energy | 4 | Link | motion is kinetic, average kinetic is temperature, temperature is thermal |