June 2014 Chemistry Regents #41-45
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Questions | Answer | Links | Explanations |
41 A 1-gram sample or a compound is added to 100 grams of H2O(l) and the resulting mixture is then thoroughly stirred. Some of the compound is then separated from the mixture by filtration. Based on Table F, the compound could be (1) AgCl (3) NaCl (2) CaCl2 (4) NiCl2 | 1 | link | insoluble compounds are generally solid in water. They get stuck in filters. See Table F FYI 3 are soluble, AgCl is insoluble |
42 At standard pressure, the total amount of heat required to completely vaporize a 100. gram sample of water at its boiling point is (1) 2.26 X 10 J (3) 2.26 X 103 J (2) 2.26 X 102 J (4) 2.26 X 105 J | 4 | link | q=mHv q= 100g x 2260J/g =226,000J or 2.26 x 105J |
43 A sample of helium gas is in a sealed, rigid container. What occurs as the temperature of the sample is increased? (1) The mass of the sample decreases. (2) The number of moles of gas increases. (3) The volume of each atom decreases. (4) The frequency of collisions between atoms increases. | 4 | link | the hotter a gas is, the faster the molecules travel and the more collision they have |
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44Given the equation representing a reaction at equilibrium : 2SO2(g) + O2(g) ==> 2SO3(g) + heat Which change causes the equilibrium to shift to the right? (1) adding a catalyst (2) adding more O2(g) (3) decreasing the pressure (4) increasing the temperature | 2 | link | increasing a reactant will cause the equilibrium to shift right |
45 Given the formula representing a compound: What is the chemical name of this compound? (1) 2-pentene (3) 3-pentene (2) 2-pentyne (4) 3-pentyne | 1 | link | 5 carbons with the double bond between carbon 2 and 3. You count from the right 2-pentene |
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