August 2007 Chemistry Regents #11-20
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Questions 1-10 Questions 11-20 Questions 21-30 Questions 31-40 Questions 41-50 |
Questions | Answer | Explanations |
| 11 Given the balanced equation representing a reaction: H+(aq) + OH-(aq) =>H2O(l ) + 55.8 kJ In this reaction there is conservation of (1) mass, only (2) mass and charge, only (3) mass and energy, only (4) mass, charge, and energy | 4 | all are conserver ALWAYS |
| 12 Which polyatomic ion contains the greatest number of oxygen atoms? (1) acetate (3) hydroxide (2) carbonate (4) peroxide | 2 | Table E |
| 13 Which formula represents an ionic compound? (1) H2 (3) CH3OH (2) CH4 (4) NH4Cl | 4 | look for the polyatomic ION (usually metal and nonmetal bonded but not here) |
| 14 An ion of which element has a larger radius than an atom of the same element? (1) aluminum (3) magnesium (2) chlorine (4) sodium | 2 | the nonmetal |
| 15 Which statement must be true when solution equilibrium occurs? (1) The solution is at STP. (2) The solution is supersaturated. (3) The concentration of the solution remains constant. (4) The masses of the dissolved solute | 3 | ConCon Requal concentrations constant rates are equal |
| 16 Which liquid has the highest vapor pressure at 75°C? (1) ethanoic acid (3) propanone (2) ethanol (4) water | 3 | Table H |
| 17 What is the total number of different elements present in NH4NO3? (1) 7 (3) 3 (2) 9 (4) 4 | 3 | count the different CAPITAL letters |
| 18 Which sample of matter is a single substance? (1) air (3) hydrochloric acid (2) ammonia gas (4) salt water | 2 | 3 are mixtures (not pure) HCl is a compound |
| 19 At STP, which sample contains the same number of molecules as 11.2 liters of CO2(g) at STP? (1) 5.6 L of NO2(g) (3) 11.2 L of N2(g) (2) 7.5 L of H2(g) (4) 22.4 L of CO(g) | 3 | Avogadro's hypothesis equal volumes contain equal numbers of molecules at the same temperature and pressure |
| 20 A sample of gas is held at constant pressure. Increasing the Kelvin temperature of this gas sample causes the average kinetic energy of its molecules to (1) decrease and the volume of the gas sample to decrease (2) decrease and the volume of the gas sample to increase (3) increase and the volume of the gas sample to decrease (4) increase and the volume of the gas sample to increase | 4 | avg KE is temperature volume and temperature are directly related Charles's Law |