H = DATA THAT YOU MAY USE. Units Conventional Volume ml or cm 3 = cm 3 or 10-3 dm 3 Liter (L) = dm 3 Pressure atm = 760 torr = 1.

Transcription

1 DATA THAT YOU MAY USE Units Conventional S.I. Volume ml or cm 3 = cm 3 or 10-3 dm 3 Liter (L) = dm 3 Pressure atm = 760 torr = Pa torr = Pa Temperature C 0 C = K PV L-atm = dm 3 Pa =101.3 dm 3 kpa =101.3 J Energy 1 cal = J (J= kg m /s ) 1 erg = 1 g cm /s = 10-7 J Current ampere (A) = 1 C/s Constants Avogadro s number N mol -1 Boltzmann s constant k J K -1 Faraday s constant F C mol -1 Values of R for various unit combinations cal mol -1 K L atm mol -1 K cm 3 atm mol -1 K J mol -1 K erg mol -1 K dm 3 kpa mol -1 K cm 3 kpa mol -1 K -1 Clausius-Clapeyron Equation P ln P1 H = R 1 T1 T vap 1 Quadratic Formula ax + bx + c = 0 b ± b 4ac x = a

2 Integrated Rate Laws Arrhenius Equation Order 0: [A] = [A] 0 k t Order 1: [A] = [A] 0 e - k t Order : 1/[A] = 1/[A] 0 + kt Ea / RT k = Ae k E a 1 1 ln = k1 R T T1 ΔG (non-standard conditions) van t Hoff Equation ΔG = ΔG + RT ln Q ln o K H 1 1 = K1 R T T1 Gas Laws PV = nrt PV 1 n T = P V n T d = MP RT m = MPV RT P = 1 3 N V mu e k = 3 RT N A 3RT u rms = P = hdg M Solutions π = imrt C=kP gas P A =χ A P A Common Strong Acids Common Strong Bases HCl LiOH Ca(OH) HBr NaOH Sr(OH) HI KOH Ba(OH) HClO 4 RbOH HNO 3 CsOH H SO 4 Mg(OH)

3 The Periodic Table of the Elements

4 1) A 10 L container holds a mixture of 5 gases at 0ºC. The composition of the mixture is given below. What is the partial pressure of N? a) 608 torr b) 800 torr c) 1340 torr d) 93 torr e) torr N (g) O (g) H (g) CO (g) He (g) 10 g 1 g 0 g 7 g 3 g ) If a liter of argon gas (Ar) is compared to a liter of neon gas (Ne), both at 75 C and two atmospheres of pressure, then: a) There are equal numbers of Ar and Ne atoms. b) The Ar and Ne atoms have the same average speed. c) The Ne atoms are on the average moving more slowly than the Ar atoms. d) The mass of one liter of Ar equals the mass of one liter of Ne. e) The average kinetic energy of the Ar atoms is greater than that of the Ne atoms. 3) Which gaseous mixture contains the largest number of moles of oxygen (O )? a) 1 L of gaseous mixture at 0ºC with an O partial pressure of 500 torr and a N partial pressure of 4000 torr b) 0 L of gaseous mixture at STP containing 50% O by volume c) A gaseous mixture of 150 g of O and 5 g N in a 10 L container d) 0.5 moles of O and 3 moles of N in a 10 L container e) 50 L of a gaseous mixture at STP with an O mole fraction (χ O ) of ) Calculate u rms, in m/s, for H (g) molecules at 30 C. a) m/s b) m/s c) m/s d) m/s e) m/s

5 5) Complete this sentence: The molecules of different samples of an ideal gas have the same average kinetic energies, at the same. a) pressure b) temperature c) volume d) density e) molarity 6) For the reaction: Kp = at 500 K. If a fixed volume is filled with initial concentrations of these gases at 7 C such that [Cl] = 0.5 M, [HO] = 0.40 M, [HCl] = 0.5 M, and [O] = M, in which direction will the reaction proceed? a) The reaction proceeds to the left. b) The reaction volume must be specified to answer this question. c) The value of Kp at 5 C must be specified to answer this question. d) The reaction proceeds to the right. e) The reaction is already at equilibrium. 7) Considering that the following reaction is exothermic, choose the correct statement: a) The reaction will be spontaneous at all temperatures. b) The reaction will be spontaneous only at low temperatures. c) The reaction will be spontaneous only at high temperature. d) The reaction is not spontaneous at any temperature. e) Both forward and reverse reactions are spontaneous. 8) For the reaction: at 98 K, Keq = and S = J/mol K. What is Keq at 00 K if H = 9.6 kj/mol? a) b) c) 16.8 d) e)

6 9) Consider the following reaction: At equilibrium at a certain temperature, [HO(g)] = 0.1 M, and [CO(g)] = [H(g)] = 1. M. If suddenly these concentrations are increased by 0.50 M, which of the following is true? a) more HO(g) will be formed b) more products are formed c) Since Kc does not change, nothing happens. d) Kc = 4.66 e) All the additional HO(g) is consumed 10) For the reaction: H = 16 kj/mol and S = J/mol K at 377 C. What is Keq? a) b) c).66 d) e) ) If G is positive for a certain reaction at a given T and P, then: a) the reverse of the reaction is spontaneous. b) the reaction is spontaneous at high temperatures. c) the system is in equilibrium. d) one would need to know the Kelvin temperature to determine spontaneity. e) the reaction is endothermic 1) For the reaction: Kc = 9.0 When equilibrium concentrations of HI and I are [HI] = M and [I] = 0.50 M, the equilibrium concentration of [H] is: a) M b) 9.56 M c) M d) M e) M

7 13) Sodium carbonate can be made by heating sodium bicarbonate. NaHCO 3 (s) Na CO 3 (s) + CO (g) + H O(g) Given that H = 18.9 kj and G = 33.1 kj at 5 C, above what minimum temperature will the reaction become spontaneous under standard state conditions? a) 0.4 K b) 3.9 K c) 31 K d) 401 K e) 55 K 14) Calculate the temperature at which Keq for a reaction is if H = -83. kj/mol and S = -46 J/mol K. a) K b) 0.74 K c) 307 K d) 74 K e) cannot be determined without G 15) Given the following: Find the value of the equilibrium constant for the following equilibrium reaction: a) b) c) d) e) ) Which of the following is a true statement about chemical equilibria in general? a) At equilibrium, the total concentration of products equals the total concentration of reactants, that is [products] = [reactants]. b) Equilibrium is the result of the cessation of all chemical change. c) There is only one set of equilibrium concentrations that equals the K c value. d) At equilibrium, the rate constant of the forward reaction is equal to the rate constant for the reverse reaction. e) At equilibrium, the rate of the forward reaction is equal to as the rate of the reverse reaction.

8 17) The equilibrium constant for the reaction: is 7. x 10-4 at 98 K and 1 atm. When [HNO(aq)] = 1.0 M and [NO - (aq)] = [H3O+(aq)] = 1.0 x 10-5 M, calculate G. a) kj/mol b) kj/mol c) kj/mol d) kj/mol e) kj/mol 18) The following reactions occur at 500 K. Arrange them in order of increasing tendency to proceed to completion (least greatest tendency). a) < 1 < 3 b) 1 < < 3 c) < 3 < 1 d) 3 < < 1 e) 3 < 1 < 19) For the formation of NO, Kc = [NO]/[NO] [O]. At equilibrium in a.50 L container, there are 3.00 mol NO, 4.00 mol O and.0 mol NO. The value of Kc is: a) 5.38 b) 33.6 c) 13.4 d) e) ) Consider the following reaction at equilibrium: The equilibrium is displaced to the left if: a) some sulfur dioxide is added b) some sulfur trioxide is removed c) the temperature is raised d) the pressure is raised e) none of these

9 1) Consider the following equilibria SO 3 (g) SO (g) + O (g) K c = NO 3 (g) NO (g) + O (g) K c = Calculate the equilibrium constant for the reaction? SO (g) + NO 3 (g) SO 3 (g) + NO (g) a) 78 b) c) d) e) ) For the following reaction K c = 8.0 at a certain temperature. NOCl(g) NO(g) + Cl (g) What concentration of NOCl must be put into an empty 4.00 L reaction vessel in order that the equilibrium concentration of NOCl will be 1.00 M? a) 1.6 M b).5 M c).50 M d) 3.5 M e) 11.0 M 3) The element oxygen was prepared by Joseph Priestley in 1774 by heating mercury(ii) oxide. HgO(s) Hg(l) + ½O (g) H = kj Use the data given below to estimate the temperature at which this reaction will become spontaneous under standard state conditions. S (Hg) = 76.0 J/K mol S (O ) = 05.0 J/K mol S (HgO) = 70.9 J/K mol a) 108 K b) 430 K c) 60 K d) 775 K e) 840 K 4) A catalyst: i) lowers activation energy ii) provides an alternate reaction pathway iii) is consumed in the reaction and therefore does not appear in the chemical equation of

10 each mechanism iv) speeds a reaction v) is heterogeneous if it is in a different phase than the reactants b) i, iii, and iv c) i, iv, and v d) ii, iii, and iv e) ii and iv f) i, ii, iv, and v 5) Define heterogeneous catalysis. a) The catalyst changes phases during the reaction. b) The catalyst is in two different phases of matter. c) The reactants and products are different phases of matter in a catalyzed reaction. d) The catalyst, reactants and products are all different phases of matter. e) The catalyst is present in a different phase of matter than are the reactants and products.