June 2017 Chemistry Regents #41-45
Highlight to reveal answers and explanations
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Questions | Answer | Links | Explanations |
41 Which particle diagram represents one substance in the gas phase? | 3 | link | gases are spread out they must be the same compounds or elements to be one substance |
42 Given the equation representing a chemical reaction at equilibrium in a sealed, rigid container: H2(g) + I2(g) + energy --> 2HI(g) When the concentration of H2(g) is increased by adding more hydrogen gas to the container at constant temperature, the equilibrium shifts (1) to the right, and the concentration of HI(g) decreases (2) to the right, and the concentration of HI(g) increases (3) to the left, and the concentration of HI(g) decreases (4) to the left, and the concentration of HI(g) increases | 2 | link | increase the concentration of a reactant, the equilibrium shifts right, producing more product HI LeChaterliers Principle |
43 Which diagram represents the potential energy changes during an exothermic reaction? | 4 | link | exothermic reactions start high go over a hill and end lower releasing energy |
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44. Which compound is classified as an ether? (1) CH3CHO (2) CH3OCH3 (3) CH3COCH3 (4) CH3COOCH3 | 2 | link | RT Table R R-O-R probably should expand them and make sure carbon has 4 bonds to spot the ether 3 is a ketone |
45 Given the equation representing a reversible reaction: HCO- (aq) + H2O(l) <--> H2CO3 (aq) + OH-(aq) Which formula represents the H+ acceptor in the forward reaction?(1) HCO- (aq) (2) H2O(l) (3) H2CO3 (aq) (4) OH-(aq)
| 1 | link | bases accept H+, they have l less hydrogen than its conjugate acid on the otherside
HCO- ==> H2CO3 |
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