January 2006 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 Compared to a calcium atom, the calcium ion Ca2+ has (1) more protons (3) more electrons (2) fewer protons (4) fewer electrons | 4 | 2+ has lost 2 electrons |
| 12 Which type of bond is found in sodium bromide? (1) covalent (3) ionic (2) hydrogen (4) metallic | 3 | ionic, metal and nonmetal |
| 13 Which substance can not be decomposed by ordinary chemical means? (1) methane (3) ethanol (2) mercury (4) ammonia | 2 | definition of an element |
| 14 A mixture of crystals of salt and sugar is added to water and stirred until all solids have dissolved. Which statement best describes the resulting mixture? (1) The mixture is homogeneous and can be separated by filtration. (2) The mixture is homogeneous and cannot be separated by filtration. (3) The mixture is heterogeneous and can be separated by filtration. (4) The mixture is heterogeneous and cannot be separated by filtration. | 2 | solutions are homogeneous mixtures and can not be separated by filtering |
| 15 Under which conditions of temperature and pressure would a sample of H2(g) behave most like an ideal gas? (1) 0°C and 100 kPa (2) 0°C and 300 kPa (3) 150°C and 100 kPa (4) 150°C and 300 kPa | 3 | ideal gas=ideal vacation high temp low pressures |
| 16 In a chemical reaction, the difference between the potential energy of the products and the potential energy of the reactants is defined as the (1) activation energy (2) ionization energy (3) heat of reaction (4) heat of vaporization | 3 | Hproducts-Hreactants=DH DH=Heat of Reaction Title of Table I |
| 17 Which substance is an Arrhenius base? (1) KCl (3) KOH (2) CH3Cl (4) CH3OH | 3 | OH-, so KOH never organic (CH3OH) alcohol |
| 18 Given the balanced equation: I2(s) + energy ==> I2(g) As a sample of I2(s) sublimes to I2(g), the entropy of the sample (1) increases because the particles are less randomly arranged (2) increases because the particles are more randomly arranged (3) decreases because the particles are less randomly arranged (4) decreases because the particles are more randomly arranged | 2 | solid lowest entropy gas highest entropy |
| 19 The multiple covalent bond in a molecule of 1-butene is a (1) double covalent bond that has 6 shared electrons (2) double covalent bond that has 4 shared electrons (3) triple covalent bond that has 6 shared electrons (4) triple covalent bond that has 4 shared electrons | 2 | -ene = double bond, share 4 electrons between carbons |
| 20 In an oxidation-reduction reaction, reduction is defined as the (1) loss of protons (3) loss of electrons (2) gain of protons (4) gain of electrons | 4 | LEO-lose electrons oxidation GER-gain electrons reduction |