June 2014 Chemistry Regents #21-25
Highlight to reveal answers and explanations
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Questions | Answer | Links | Explanations |
| 21 Given the balanced equation representing a reaction: O2 --> O + O What occurs during this reaction? (1) Energy is absorbed as bonds are broken. (2) Energy is absorbed as bonds are formed. (3) Energy is released as bonds are broken. (4) Energy is released as bonds arc formed. | 1 | link | the molecule is broken down into atoms breaking bonds requires energy |
| 22 In terms of entropy and energy, systems in nature tend to undergo changes toward (1 ) lower entropy and lower energy (2) lower entropy and higher energy (3) higher entropy and lower energy (4) higher entropy and higher energy | 3 | link | nature tends to go towards lower energy and more randomness think Lord of the Flies....chaos and fire |
| 23 Which term is defined as the difference between the potential energy of the products and the potential energy of the reactants in a chemical reaction? (1) activation energy (3) heat of fusion (2) thermal energy (4) heat of reaction | 4 | link | heat of reaction=Energy products- Energy reactants |
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| 24 What is the atomic number of the element whose atoms bond to each other in chains, rings, and networks? (1) 10 (3) 6 (2) 8 (4) 4 | 3 | link | Carbon is the element with the atomic #6 |
| 25 How many pairs of electrons are shared between two adjacent carbon atoms in a saturated hydrocarbon?
(1) 1 (3) 3 (2) 2 (4) 4 | 1 | link | saturated is all single bonds a single bond is 2 shared electrons or 1 PAIR |
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