June 2012 Chemistry Regents #21-30
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Questions | Answer | Links | Explanations |
21 Which type of concentration is calculated when the grams of solute is divided by the grams of the solution, and the result is multiplied by 1 000 000? (1) molarity (2) parts per million (3) percent by mass (4) percent by volume | 2 | link | ummm, PPM Table T |
22 Which type of energy is associated with the random motion of atoms and molecules in a sample of air? (1) chemical energy (2) electrical energy (3) nuclear energy (4) thermal energy | 4 | link | energy of motion is kinetic energy avg. KE is temperature (thermal) |
23 The temperature of a sample of matter is a measure of the (1) total kinetic energy of the particles in the sample (2) total potential energy of the particles in the sample (3) average potential energy of the particles in the sample (4) average kinetic energy of the particles in the sample | 4 | link | avg. KE is temperature |
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24 What unit is used to express the pressure of a gas? (1) mole (2) joule (3) kelvin (4) pascal | 4 | link | On table D |
25 Which sample of matter sublimes at room temperature? (1) Br2(l) (2) Cl2(g) (3) CO2(S) (4) SO2(aq) | 3 | link | CO2(s) is dry ice and sublimes |
26 Given the diagram representing a closed system at constant temperature: Which statement describes this system at equilibrium? (1) The mass of H2O(l) equals the mass of H2O(g) (2) The volume of H2O(l) equals the volume of H2O(g) (3) The number of moles of H2O(l) equals the number of moles of H2O(g) (4) The rate of evaporation of H2O(l) equals the rate of condensation of H2O(g) | 4 | link | at equilibrium Con Con Requal concentrations constant rates are equal |
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27 Which reaction occurs at the cathode in an electrochemical cell? (1) combustion (2) neutralization (3) oxidation (4) reduction | 4 | link | RedCat AnOX |
28 Which yields H+(aq) as the only positive ion in an aqueous solution? (1) CH3CHO (2) CH3CH2OH (3) CH3COOH (4) CH3OCH3 | 3 | link | H+ ...acid..Table K CH3COOH |
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29 Compared to the mass and the penetrating power of an alpha particle, a beta particle has (1) less mass and greater penetrating power (2) less mass and less penetrating power (3) more mass and greater penetrating power (4) more mass and less penetrating power | 1 | link | beta is an electron alpha is helium helium is stopped easier than an electron |
30 During a nuclear reaction, mass is converted into (1) charge (2) energy (3) isomers (4) volume | 2 | link | mass turns into energy E=mc2 |