June 2014 Chemistry Regents #26-30
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Questions | Answer | Links | Explanations |
26 Given the balanced equation representing a reaction: 4Al(s) + 3O2(g) ==> Al2O3(s) As the aluminum loses 12 moles of electrons, the oxygen (1) gains 4 moles of electrons (2) gains 12 moles of electrons (3) loses 4 moles of electrons (4) loses .12 moles of electrons | 2 | link | law of conservation of charge electrons lost must equal electrons gained |
27 Which compound is an electrolyte? (I) CH3CHO (3) CH3COOH (2) CH3OCH3 (4) CH3CH2CH3 | 3 | link | acids bases and salts are electrolytes CH3COOH is a weak acid See Table K |
28 Which statement describes one acid-base theory? (1) An acid is an H+ acceptor, and a base is an H+ donor. (2) An acid is an H+ donor,. and a base is an H+ acceptor. (3) An acid is an H- acceptor, and a base is an H-donor. (4) An acid is an H- donor, and a base is an H acceptor. | 2 | link | Bronsted Lowry acid base definitions |
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29 Which compounds are classified as Arrhenius acids? (1) HCl and NaOH (2) HNO3 and NaCl (3) NH3 and H2CO3 (4) HBr and H2SO4 | 4 | link | Arrhenius acids Start with Hydrogen also see table K |
30 Which statement describes the stability of the nuclei of potassium atoms? (1) All potassium atoms have stable nuclei that spontaneously decay. (2) All potassium atoms have unstable nuclei that do not spontaneously decay. (3) Some potassium atoms have unstable nuclei that spontaneously decay. (4) Some potassium atoms have unstable nuclei that do not spontaneously decay. | 3 | link | all atoms have unstable isotopes that spontaneously decay based on the ratio of protons to neutrons some atoms have stable nuclei that do not decay |
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