January 2016 Chemistry Regents #36-40
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Questions | Answer | Links | Explanations |
| 36 Which sample, when dissolved in 1.0 liter of water, produces a solution with the highest boiling point? (1) 0.1 mole KI (3) 0.1 mole MgCl2 (2) 0.2 mole KI (4) 0.2 mole MgCl2 | 4 | vant hoff factor is greater for MgCl2 (more ions in the formula) | |
| 37 Given the balanced equation representing a reaction: 4NH3(g) + 5O2(g) → 4NO(g) + 6H2O(g) What is the number of moles of H2O(g) formed when 2.0 moles of NH3(g) react completely? (1) 6.0 mol (3) 3.0 mol (2) 2.0 mol (4) 4.0 mol | 3 | ||
| 38 A rigid cylinder with a movable piston contains a sample of gas. At 300. K, this sample has a pressure of 240. kilopascals and a volume of 70.0 milliliters. What is the volume of this sample when the temperature is changed to 150. K and the pressure is changed to 160. kilopascals? (1) 35.0 mL (3) 70.0 mL (2) 52.5 mL (4) 105 mL | 2 | (240.*70.0)/300=(V * 160.)/150. | |
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| 39 A 100.-gram sample of H2O(L) at 22.0°C absorbs 8360 joules of heat. What will be the final temperature of the water? ( 1 ) 18.3°Ꮯ (3) 25.7°C (2) 20.0°Ꮯ (4) 42.0°Ꮯ | 4 | First temperature increases. (1 and 2 are out) q=mCDT DT=q/mC=8360J/(100.*4.18J/goC) DT=200C 22 +20=42 | |
| 40 Which compound has the strongest hydrogen bonding at STP? (1) H2O (2) H2S (3) H3Se (4) H3Te | 1 | H with F,O or N
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