Flashcards for the equilibrium unit.
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| 1993182243 | Reversible reactions are those that occur ___. Some reactions can go to ___, which is when you use a one-way arrow. Most do not however, and require a ___. | both forward & backwards; completion; two-way arrow | 0 | |
| 1993190071 | Reactions that do not go to completion reach a ___ where reactants continually turn into products and vice-versa. Usually they are expressed in ___. | dynamic state; closed systems | 1 | |
| 1993195934 | ___ describes the rates of reactions. While the ___ of chemical compounds doesn't become equal, the ___ do. | Chemical kinetics; concentrations; rates | 2 | |
| 1993200226 | With chemical kinetics, the reactants' rate of reaction ___ while the products ___. The products' rates begin low, but as more appear, their ___ increase, so the rate increases. | decreases until equilibrium; increases until equilibrium; collisions | 3 | |
| 1993219758 | Reactions ___ once equilibrium is reached. The ___ are just equal. ___ of species generally remains ___ after equilibrium, but rarely they are the same to one another. | still occur; rates; concentrations; constant | 4 | |
| 1993227440 | Writing Equilibrium Expressions | • aA + bB ⇌ dD + eE • K(c) = ([D]^d∙[E]^e)/([A]^a∙[B]^b) | 5 | |
| 1993235693 | The units for concentration in equilibrium expressions is ___. ___ represents concentrations, while ___ represents partial pressures. | molar (mol/liter); square brackets; (P) | 6 | |
| 1993243268 | Combustion reactions are always ___. | exothermic | 7 | |
| 1993245311 | ___ is the generic equilibrium constant. All others are just more specific versions. | K(eq) | 8 | |
| 1993249403 | You leave ___ out of equilibrium expressions because the ___ won't change as they have same ___. You leave ___ out of equilibrium expressions because ___ does not affect the overall concentration of the solvent. | solids; concentration; density; adding/removing small amounts of solute | 9 | |
| 1993259329 | The ___ of a gas in a system is the pressure exerted by a specific gas. The sum of partial pressures is equal to ___ of the system. ___ will exert equal pressures under the same conditions of volume and temperature. Two moles of gas exerts ___ as much pressure. | partial pressure; total pressure; Equal moles of different gases; twice | 10 | |
| 1993267616 | Converting Between K(c) and K(p) | • K(p) = K(c)(RT)^Δn • R = Ideal Gas Constant • T= Temperature in Kelvin • Δn = (moles of GASEOUS products)-(moles of GASEOUS reactants) | 11 | |
| 1993282794 | What K(eq) Tell Us | • K(eq) > 10 - Mostly products, equilibrium lies far to the right • K(eq) < 0.1 - Mostly reactants, equilibrium lies far to the left • K(eq) ≈ 1 - Equal amounts of each, equilibrium lies to the middle | 12 | |
| 1993309926 | Whenever asked to find values of a system at equilibrium, you must use an ___. When ___, you can ignore subtracting the x-value from the reactants. | Initial, Change, Equilibrium (ICE) Chart; K(eq) < 1 x 10^-4 | 13 | |
| 1993323372 | ICE Chart Checks | 1) Compare the amount that should be subtracted from the reactants to the amount of reactants, if it is significantly less it will have no significant effect 2) Substitute x into the equilibrium expression (with reactants not subtracted by x), and see if the K(c) value is similar to the original one | 14 | |
| 1993413457 | The ___ is calculated utilizing the same steps as the equilibrium expression, but show's the state of the system at a ___. Systems are at equilibrium when ___. Whether products/reactants are needed to achieve equilibrium will determine if the ___ is favored. | reaction quotient (Q); particular time; Q = KQ; forward or reverse reaction | 15 | |
| 1993433993 | Comparing the Reaction Quotient & K(eq) | • Q > K(eq) - The reaction will proceed to the left, increasing the concentration of the reactants • Q < K (eq) - The reaction will proceed to the right, increasing the concentration of the products • Q = K(eq) - The system is at equilibrium | 16 | |
| 1993448789 | ___ states that when a system at equilibrium is subjected to a ___, the equilibrium will shift in order to ___ it. | Le Châtelier's Principle; stress; reduce | 17 | |
| 1993467674 | ___ and ___ do not change K(eq), they just change the concentrations. ___ changes both. | Pressure; concentrations; Temperature | 18 | |
| 1993463269 | If a pressure on a system at equilibrium is increased, equilibrium shifts to the side with ___ and ___. If the volume is reduced by a factor of 2, the pressure ___ and the molar concentrations of all species ___. | fewer moles of gas; more condensed states; doubles; double | 19 | |
| 1993478653 | When the volume decreases of a system, the ___ between particles increases. This increases the rate of both ___ reactions. The rate of the reaction that brings the system to equilibrium ___ will be quicker. | collision rate; forward and reverse; faster | 20 | |
| 1993483878 | If pressure on a system at equilibrium is decreased, equilibrium shifts to the side with ___. If there is the same number of moles of gas on both sides, the ___ will change when the volume changes, but the ___. | more moles of gas; pressure; equilibrium will not shift | 21 | |
| 1993492595 | If the concentration of one of the species in an equilibrium system is increased, equilibrium shifts in the direction that ___. If the concentration of one species decreases, equilibrium shifts in the direction that ___. | reduces the concentration of that species; increases the concentration of that species | 22 | |
| 1993504877 | If a solvent is added to a system at equilibrium, the equilibrium shifts toward the side with ___ to reduce that stress. This increases the ___ and decreases the ___. | more particles; volume; concentration | 23 | |
| 1993517364 | If heat is changed, equilibrium shifts to reduce that stress. Adding heat causes an increase in the ___. It causes a decrease in the ___. Extra energy is stored in the ___. | rate of an endothermic reaction; rate of an exothermic reaction; bonds of compounds | 24 | |
| 1993523990 | K(eq) changes when heat is added because it ___. Removing heat favors production of compounds that possess ___. | affects the concentration of compounds unevenly on one side; less energy in their bonds | 25 | |
| 1993609957 | In the reciprocal rule, ___ stays the same, but the K(eq) value changes. Just take the ___ of a reaction's K(eq) value to find the reverse reaction. | equilibrium; reciprocal | 26 | |
| 1993617885 | When two or more reactions are combined, the ___ allows us to ___ the two K(eq) values to find the new one. | multiple equilibria rule; multiply | 27 | |
| 2028179225 | ΔG must be ___ for a reaction to proceed in a given direction. ΔG is the ___. | less than zero; maximum amount of work that can be done by a system | 28 | |
| 2028182460 | A system is at equilibrium when it is ___. Although forward and reverse reactions continue to take place at equilibrium, net changes in ___ are not possible. ___ is directly related to ΔG. | no longer able to do any work (ΔG = 0); concentration; K(eq) | 29 | |
| 2028204762 | When ΔG < 0, the process favors ___ at equilibrium and K(eq) is ___. The reaction will proceed to equilibrium in ___. The reaction is considered "___". | products; > 1; either direction; exergonic | 30 | |
| 2028221848 | When ΔG > 0, the process favors ___ at equilibrium and K(eq) is ___. The reaction will proceed to equilibrium in ___. The reaction is considered "___". | reactants; < 1; either direction; endergonic | 31 | |
| 2028228231 | A process that is non-thermodynamically favored will produce products if system initially contains only ___. If the products are removed, the equilibrium will shift in order to ___. | reactants; produce more products | 32 | |
| 2028257626 | ΔG° indicates ___. This means all species exist as ___, all gases have partial pressures of ___. All aqueous species have ___ concentrations. The temperature of the system is ___. | standard state; pure substances; 1 atm; 1 M; 298.15K | 33 | |
| 2028276483 | Different temperatures, but everything the else same as standard state for ΔG is indicated by ___. ___ is the maximum amount of work that can be done by a system as it moves ___. ΔG°T is the same, but at ___. | ΔG°T; ΔG°; 100% reactants → 100% products at standard temperatures; non-standard temperatures | 34 | |
| 2028289549 | Relating ΔG° to K(eq) with Equations | • ΔG° = -RT∙ln(K(eq)) • K(eq) = e^(-ΔG°/RT) • ΔG° must be in J/mol • T must be in K • K(eq) must be calculated using partial pressures for gases and molar concentrations for aqueous species | 35 | |
| 2028331544 | Estimations of Equilibrium Expressions | • RT ≈ 2400 J/mol @ standard states • ΔG° >> 2400 J/mol, then K << 1 • 2400 J/mol > ΔG° > -2400 J/mol, then K≈1 • ΔG°<< -2400 J/mol, then K >> 1 | 36 | |
| 2028376978 | Estimation of K(eq) Relating to ΔG° | ΔG°> 0, K(eq) < 1 = Mostly reactants ΔG° > +20 kJ, K(eq) << 1 = Virtually all reactants ΔG° < 0, K(eq) > 1 = Mostly products ΔG° < -20 kJ, K(eq) >> 1 = Virtually all products | 37 | |
| 2028616294 | To tell if a process is thermodynamically favorable, use the equation: ___. You can tell it is thermodynamically without the equation if: ___. | ΔG° = ΔH° - TΔS°; ΔH° < 0 and ΔS° > 0 | 38 | |
| 2035534772 | If water is added to a system, it will shift to ___. | the side with more moles | 39 |
