August 2015 Chemistry Regents #26-30
Highlight to reveal answers and explanations
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Questions | Answer | Links | Explanations |
| 26 Based on the Arrhenius theory, when potassium hydroxide dissolves in water, the only negative ion in the aqueous solution is (1) O2- (aq) (3) H- (aq) (2) OH2- (aq) (4) OH- (aq) | 4 | link | hydroxide= OH- |
| 27 Compared to distilled water, an aqueous salt solution has (1) better electrical conductivity (2) poorer electrical conductivity (3) a lower boiling point at standard pressure (4) a higher freezing point at standard pressure | 1 | link | moving charge when salt dissolves= conductivity |
| 28 According to one acid-base theory, water can act as a base because a water molecule can (1) donate an H+ ion (3) donate an H- ion (2) accept an H+ ion (4) accept an H- ion | 2 | link | Bases accept H+ |
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| 29 Compared to the half-life and decay mode of the nuclide 90Sr, the nuclide 226Ra has (1) a longer half-life and the same decay mode (2) a longer half-life and a different decay mode (3) a shorter half-life and the same decay mode (4) a shorter half-life and a different decay mode | 2 | link | Use Table N for both |
| 30 Which net change occurs in a nuclear fusion reaction? (1) Ionic bonds are broken. (2) Ionic bonds are formed. (3) Energy is converted to mass. (4) Mass is converted to energy. | 4 | link | E=mc2 mass turns into a lot of energy |
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