7. A solution has the following concentrations: [Cl - ] = 1.5 x 10-1 M [Br - ] = 5.0 x 10-4 M

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1 Solubility, Ksp Worksheet 1 1. How many milliliters of 0.20 M AlCl 3 solution would be necessary to precipitate all of the Ag + from 45ml of a 0.20 M AgNO 3 solution? AlCl 3(aq) + 3AgNO 3(aq) Al(NO 3) 3(aq) + 3AgCl(s) (A) 15 ml (B) 30 ml (C) 45 ml (D) 60 ml 2. Which of the following salts has the greatest molar solubility in pure water? (A) CaCO 3 ( K sp = 8.7 x 10-9 ) (B) CuS (K sp = 8.5 x ) (C) Ag 2CO 3 ( K sp = 6.2 x ) (D) Pb(IO 3) 2 ( K sp = 2.6 x ) 3. The solubility product of CaF 2 is 4.3 x What is the molar solubility of CaF 2 in a M solution of Ca(NO 3) 2? (A) 2.2 x 10-4 M (B) 1.0 x 10-5 M (C) 1.5 x 10-5 M (D) 8.4 x M 4. Silver oxalate Ag 2(C 2O 4) is dissolved in pure water. The concentration of Ag + ion in a saturated solution is 2.2 x 10-4 M. What is the K sp of Ag 2(C 2O 4)? (A) 5.3 x (B) 1.1 x 10 1 (C) 5.0 x 10-8 (D) 2.4 x 10-8 (E) 2.2 x What weight of silver chromate (Ag 2CrO 4) will dissolve in 1.0 liter of a solution that is M in Ag +? K sp Ag 2CrO 4 = 1.9 x MW Ag 2CrO 4 = 332 g/mol. (A) 1.9 x g (B) 1.9 x 10-8 g (C) 1.4 x 10-6 g (D) 6.3 x 10-6 g (E) 4.7 x 10-4 g 6. The solubility of CaF 2 in 1 x 10-3 M KF (A) is equal to the solubility of CaF 2 in pure water. (B) is less than the solubility of CaF 2 in pure water. (C) is greater than the solubility of CaF 2 in pure water. 7. A solution has the following concentrations: [Cl - ] = 1.5 x 10-1 M [Br - ] = 5.0 x 10-4 M 2- [CrO 4 ] = 1.9 x 10-2 M A solution of AgNO 3 (100% dissociated) is added to the above solution, drop by drop. Which silver salt will precipitate first? K sp AgCl = 1.5 x K sp AgBr = 5.0 x K sp Ag 2CrO 4 = 1.9 x (A) AgCl (B) AgBr (C) Ag 2CrO 4 (D) AgCl and AgBr together (E) none of the above

2 8. Suppose that CaF 2 is to be used as a fluoridation agent in a municipal water system. What is the [F - ] if extremely hard water ([Ca 2+ ] = M) is saturated with CaF 2? (Ksp CaF 2 = 1.7 x ) (A) 1.3 x 10-5 M (B) 2.5 x 10-5 M (C) 5.0 x 10-5 M (D) 1.0 x 10-4 M (E) M 9. Which of the following salts is most soluble in water? (A) Mg(OH) 2 (B) CaS (C) (NH 4) 2CO 3 (D) PbCl A 2.00 g sample of a compound requires ml of M AgNO 3 to precipitate all of the chloride ion in the compound. What is the percent of Cl - in the compound? (AW of Cl = g/mol) (A) 47.6% (B) 95.1% (C) 23.8 % (D) 4.75 % 11. Predict what effect each of the following has on the position of the equilibrium. PbCl 2 Pb 2+ (aq) + 2Cl - (aq) ΔH = KJ (A) The addition of Pb(NO 3) 2 solution. (B) Increase the temperature. (C) The addition of Ag +. (D) The addition of HCl. 12. Which salt is the least soluble in water? (A) Hg 2CrO 4 (K sp = 2.0 x 10-9 ) (B) BaF 2 (Ksp = 1.7 x 10-6 ) (C) CaF 2 (K sp = 4.0 x ) (D) AgOH (K sp = 1.5 x 10-8) (E) BaCO 3 (K sp = 8.0 x 10-9) Solubility, Ksp Answer Key WORKSHEET 1 1) A 2) A 3) C 4) A 5) D 6) B 7) C 8) C 9) C 10) A 11) a) drives rxn to the left b) drives rxn to the right c) drives rxn to the right d) drives rxn to the left 12) C

3 Kinetics Worksheet 1 1. The rate of a chemical reaction between substances A and B is found to follow the rate equation rate = k[a] 2 [B] where k is a constant. If the concentration of A is halved, what should be done to the concentration of B to make the reaction go at the same rate as before? (A) The concentration of B should be kept constant. (B) The concentration of B should be doubled. (C) The concentration of B should be halved. (D) The concentration of B should be quadrupled. 2. The rate expression for a second-order reaction could be (A) rate = k[a] (B) rate = k[a] 2 [B] (C) rate = k[a][b] (D) rate = k[a] 2 [B] 2 3. The half-life of 14 C is 5570 years. How many years will it take for 90% of a sample to decompose? (A) 5,570 years (B) 17,700 years (C) 18,600 years (D) 50,100 years 4. The slowest step of a reaction is called the (A) elementary process. (C) order. (B) molecularity. (D) rate-determining step. 5. For a first-order reaction of half-life, 150 min., what is the rate constant in min -1? (A) (B) (C) 69.3 (D) The rate of the reaction 2NO + Cl 2 2 NOCl is given by the rate equation rate = k[no] 2 [Cl 2]. The value of the rate constant can be increased by: (A) increasing the concentration of NO. (B) increasing the concentration of Cl 2. (C) increasing the temperature. (D) doing all of these. 7. For a certain reaction the rate law is, rate = k[c] 3/2. If the rate of the reaction is M s -1 when [C] = 1.0 M, what is the rate when [C] = 0.60 M? (A) M s -1 (B) M s -1 (C) M s -1 (D) M s 1

4 8. The rate of the reaction 2A + B -----> Products is consistent with first-order kinetics for both A and B. Which reaction mechanism is consistent with this information? (A) A + B -----> AB (slow) AB + A -----> Products (fast) (B) A + A -----> A 2 (slow) A 2 + B -----> Products (fast) (C) A + B -----> AB (fast) AB + A -----> Products (slow) (D) A + A -----> A 2 (fast) A 2 + B -----> Products (slow) 9. The dissociation of HI molecules, as shown below, occurs at a temperature of 629 K. The rate constant, k = 3.02 x 10-5 M -1 s -1. What is the reaction order? 2HI(g) H2(g) + I2(g) (A) 0 (B) 1 (C) 2 (D) The rate constant of a reaction is generally expected to (A) be independent of temperature. (A) decrease with increasing temperature. (C) increase with increasing temperature. (D) increase with increasing temperature, only if the reaction is endothermic. 11. The rate law of the reaction 2 H NO -----> N H 2 O is second order in [NO] and first order in [H 2 ]. If [NO] is doubled and [H 2 ] is halved, the rate of the reaction will (A) increase by a factor of 4. (B) remain the same. (C) increase by a factor of 6. (D) increase by a factor of The rate of a second order decomposition of a substance, A, is 2.7 M s -1 when the initial concentration of the reactant A is 0.60 M. What is the initial rate of the reaction when the initial concentration of the reactant is 0.20 M? (A) 0.30 M s -1 (B) 0.60 M s -1 (C) 0.90 M s -1 (D) 2.7 M s The decomposition of NaClO 3 is a first-order reaction. In an experiment, a sample of NaClO 3 was 90% decomposed in 48.0 minutes. How long would it take for a sample to be 50% decomposed? (A) 14.4 min (B) 21.6 min (C) 24.0 min (D) 43.2 min (E) 48.0 min

5 Kinetics Worksheet 2 Questions 1-3 refer to these data for the reaction: 2NO(g) + 2H 2(g) N 2(g) + 2H 2O(g) Run Pressure(NO) atm Pressure(H 2 ) atm Rate atm/s x x x l x What is the rate law equation for this reaction? (A) Rate = k [P NO] (B) Rate = k [P NO] 2 [P H2] (C) Rate = k [P NO][P H2] 2 (D) Rate = k [P NO][P H2] (E) Rate = k [P NO] 2 2. If both the [NO] and the [H 2] were initially at atm, the initial rate of the reaction would be: (A) 9.00 x 10-3 atm/s (B) 1.80 x 10-2 atm/s (C) 2.70 x 10-2 atm/s (D) 3.60 x 10-2 atm/s (E) 7.30 x 10-2 atm/s 3. The value of the rate constant, k, is: (A) 9.14 x 10-3 atm s -1 (B) 9.14 x 10-3 atm -1 s -1 (C) 9.14 x 10-3 atm -2 s -1 (D) 9.14 x 10-4 atm 3 s (E) 9.14 x 10-4 atm 4 s What conclusion can be made from the data given? The rate determining step: (A) of a catalyzed reaction is faster. (B) is not assumed from the stoichiometry of the reaction. (C) is the fastest step. (D) is the slowest step. (E) at a temperature 10 o C higher doubles the rate. 5. An approximate rule is that an increase in temperature of 10 o C will double the reaction rate. Which is doubled on the molecular level? The: (A) activation energy. (B) average kinetic energy. (C) average velocity of molecules. (D) fraction of molecules with the activation energy. (E) number of collisions. 6. The half-life of Po-210 is 140 days. What mass of a 2.00 g sample will be left after 700 days? (A) 1.00 (B) 0.50 g (C) 0.25 g (D) 0.12 g (E) 0.06 g

6 7. In the reaction A + B C, the following data were obtained: [A] [B] rate M s The data are consistent with which of the following rate laws? (A) k[a][b] (B) k[a] (C) k[b] (D) k (E) k[a] 2 [B] 8. Which is true of all zero order reactions? (A) E a = 0. (B) k = 0. (C) Reactant concentration does not change with time. (D) The rate is independent of time. (E) The rate is immeasurably slow. 9. For a first order reaction, a curve (something that's not a straight line) is obtained for the following except: (A) [A] vs. t (B) log[a] vs. t (C) 1/[A] vs. t (D) [A] vs. 1/t (E) log k vs. 1/t Kinetics Answer Key WORKSHEET 1 1) D 2) C 3) C 4) D 5) B 6) C 7) A 8) A 9) C 10) C 11) D 12) A 13) A WORKSHEET 2 1) B 2) E 3) C 4) B 5) E 6) E 7) B 8) A 9) B

7 Equilibrium Worksheet 1 For questions 1-3, consider the reaction: Fe 2O 3(s) + 3H 2(g) 2Fe(s) + 3H 2O (g) ΔH= 15 kj 1. The equilibrium concentrations under certain conditions were found to be [H 2O] = 1.0 M [H 2] = 2.5 M What is the value for K? (A) 0.40 (B) (C) 15.6 (D) Insufficient information to calculate. 2. K p is (A) less than K. (B) greater than K. (C) equal to K. (D) insufficient information to calculate. 3. Use the following choices: (A) Shift left (B) Shift right (C) No change (D) Not possible to predict to indicate the effect of each of the following stresses on the position of this system at equilibrium: (i) Decrease the volume of the container. (ii ) Add Fe 2O 3(s) (iii) Remove H 2O(g) (iv) Increase the temperature. 4. For the reaction: 4 NH 3(g) + 5O 2(g) 4NO(g) + 6H 2O(g) ΔH is negative. The position of this equilibrium would be shifted to the left by (A) removing NO(g). (B) adding O 2(g). (C) increasing the pressure by decreasing the volume of the container. (D) decreasing the temperature. (E) none of these. 5. Calculate the equilibrium constant for the following reaction: 2A(g) B(g) + 3C(g) given that a 1.0 L vessel was initially filled with 5.0 atm of pure A and the partial pressure of gas A was found to be 3.5 atm at equilibrium. (A) 11.1 atm 2 (B) 0.70 atm 2 (C) 3.8 atm 2 (D) 0.48 atm 2 6. Increasing the volume of the reaction vessel in question 5 would have what effect? (A) Increase the equilibrium constant. (B) Force the reaction to proceed to the right. (C) Force the product ratio [C]/[B] to be greater than 3. (D) Only (A) and (B) are correct. (E) (A), (B), and (C) are correct. Equilibrium Answer Key 1) B 2) C 3.i) C 3.ii) B 3.iii) B 3.iv) B 4) C 5) E 6) D

8 Acids and Bases Worksheet 1 1. The acid HX has an ionization constant of 1 x A solution is 0.1 M in HX and 1 M in the salt NaX. What is a close approximation of the hydrogen ion concentration? (A) 10 3 M (B) 2 x 10-3 M (C) 10-5 M (D) 10-8 M 2. How many moles of pure NaOH must be used to prepare 10.0 L of a solution that has a ph of 13.00? (A) 1.0 mol (B) 0.10 mol (C) mol (D) mol 3. Consider the reaction CH 3NH 2(aq) + H 2O(l) CH 3NH 3 (aq) + OH - (aq) where K b = 4.4 X To a solution formed from the addition of 2.0 mol CH 3NH 2 to 1.0 L of H 2O is added 1.0 mol of KOH (assume no volume change on addition of solutes). What is the concentration of CH 3NH + 3 at equilibrium? (A) 3.2 x 10-2 M (B) 2.2 x 10-4 M (C) 2.0 x 10-3 M (D) 8.8 x 10-4 M 4. A 0.20 M solution of the hypothetical weak acid HZ is found to have a ph of exactly 3.0. The ionization constant, K a, of the acid HZ is: (A) 0.6 (B) 1.0 x10-3 (C) 2.0 x 10-4 (D) 5.0 x A buffer solution is formed by adding mol of sodium acetate and mol of acetic acid to 1.00 L H 2O. What is the ph of the solution at equilibrium? (K a = 1.80 X 10-5 ) (A) 5.05 (B) 4.74 (C) 4.44 (D) Which statement is a logical consequence of the fact that a 0.10 molar solution of potassium acetate, KC 2H 3O 2, is less basic than a 0.10 molar solution of potassium cyanide, KCN? (A) Hydrocyanic acid (HCN) is a weaker acid than acetic acid. (B) Hydrocyanic acid is less soluble in water than acetic acid. (C) Cyanides are less soluble than acetates. (D) Acetic acid is a weaker acid than hydrocyanic acid. 7. Which species is most likely to function both as an acid and as a base? (A) Cl (B) H 2O (C) NH 4 + (D) H 3O + 8. If the pk a of the acid HX is 8.0, the K b for X - is

9 (A) 10 8 (B) 10-8 (C) 10 6 (D) What is the ph of a 1.0 M solution of aniline? (K b = 4 x ) (A) 4.7 (B) 9.3 (C) 9.4 (D) None of these 10. Which of the following is a base-conjugate acid pair? (A) C 6H 5NH 2, C 6H 5NH 3 + (B) Cl -, NH 4 + (C) NH 3, HC 2H 3O 2 (D) HC 2H 3O 2, H 2O 11. The amount (in grams) of sodium acetate (MW = 82.0 g/mol) to be added to ml of molar acetic acid (Ka = 1.80 X 10-5 ) in order to make a buffer with ph = is (A) 69 (B) C) 14.8 (D) A 0.30 M solution of a weak acid (HA) has an [H + ] of 1.66 x10-4 M. What is the K a of this weak acid? (A) 4.8 x 10 1 (B) 5.5 x 10-4 (C) 1.2 x 10 8 (D) 9.2 x 10-8 (E) The K a cannot be calculated without additional information. 13. What volumes of M HNO 2 (K a = 4.0 X 10-4 ) and M NaNO 2 must be mixed to prepare 1.0L of a solution buffered at ph 3.55? (A) 500 ml of each solution (B) 703 ml M HNO 2, 297 ml M NaNO 2 (C) 413 ml M HNO 2, 587 ml M NaNO 2 (D) 297 ml M HNO 2, 703 ml M NaNO 2 (E) 587 ml M HNO 2, 413 ml M NaNO 2 Acids and Bases Answer Key WORKSHEET 1 1) C 2) A 3) D 4) D 5) B 6) A 7) B 8) D 9) B 10) A 11) C 12) D 13) C

10 Acids and Bases Worksheet 2 1. In the reaction: 2- CO 3 + H 2O - HCO 3 + OH - the carbonate ion is acting as a(n): (A) Arrhenius base (B) Arrhenius acid (C) Bronsted-Lowry base (D) Bronsted-Lowry acid 2. Which of the following represents a Bronsted-Lowry conjugate acid-base pair? (A) SO 3 2- and SO 2 (B) CO 3 2- and CO C) H 3O + and H 2 D) NH 4 + and NH 3 3. Which of the following would not make a good buffering system? (A) SO 4 2- and H 2SO 4 (B) HCO 3- and H 2CO 3 (C) NH 3 and NH 4 + (D) CH 3COO- and CH 3COOH 4. A water solution of which of the following compounds will turn blue litmus red (A) K 2CO 3 (B) NH 4Cl (C) NaOH (D) NaCl ml of a solution of HCl required 12.5 ml of M Ba(OH) 2 for complete neutralization. How many moles of HCl were present in the sample? (A) 5.00 x l0-3 (B) 1.00 x 10-2 (C) 1.00 (D) If 1.00 L of 1.00 M CH 3COOH is mixed with 0.25 mole of solid NaOH (assume no volume change), what will be the ph of the resulting solution? (K a = 1.8 x 10-5 ). (A) (B) 4.27 (C) 4.74 (D) What is the molarity of CH 3COOH in vinegar containing 4.0% CH 3COOH by mass and having a density of 1.02 g/ml? (A) 0.50 M (B) 0.68 M (C) 0.75 M (D) 1.36 M 8. If 5.00 ml of 15.4 M HNO 3 is diluted to 250 ml, what is the ph of the resulting solution? (A) 0.51 (B) 0.76 (C) 1.45 (D) 2.89

11 9. The ph of a 0.10 M solution of a weak acid is What is the K a of the acid? (A) 1.6 x (B) 3.2 x (C) l.6 x 10 8 (D) 8.0 x Which solution would show the least change in ph upon addition of 3.0 ml of 1.0 M KOH? (Assume equal volumes of each solution are used. K a for HC 2H 3O 2 = 1.8 x 10-5 ) (A) A solution that is 0.50 M acetic acid and 0.50 M sodium acetate. (B) A solution that is 0.10 M acetic acid and 0.10 M sodium acetate. (C) A solution that is 1.0 M acetic acid. (D) A solution that is 0.50 M sodium acetate. 11. A 50.0 ml solution of 1.50 M NaOH is being titrated with a 2.00 M HCI solution. What will the ph be after the addition of 35.0 ml of HCI? (A) 1.23 (B) 11.7 (C) 12.8 (D) 2.3 (E) A strong monoprotic acid is being titrated with a M NaOH solution. Which statement is true, for this titration? (A) The ph at the equivalence point cannot be determined without knowing the identity of the acid. (B) The ph at the equivalence point cannot be determined unless the concentration of the acid is known. (C) The ph at the equivalence point depends on neither the identity of the acid nor on the concentration of the acid. 13. Consider the titration of ml of M NH 3 with M HCl. After 50.0 ml of HCl has been added the [H + ] of the solution is: (A) 1.8 x l0-5 M (B) 5.6 x M (C) 1.2 x10-5 M (D) None of these 14. What volume of M NaOH must be added to 1.00 L of M HA (K a = 4.0 x 10-8 ) to achieve a ph of 8.00? (A) 1.00 L (B) 5.00 L (C) 2.00 L (D) 4.00 L 15. In the titration of a weak acid, HA, with M NaOH, the stoichiometric point is known to occur at a ph value of approximately Which of the following indicator acids would be best to use to mark the endpoint of this titration? (A) Indicator A, K a = (B) Indicator B, K a = (C) Indicator C, K a = 10-8 (D) Indicator D, K a = 10-6 will work well. Acids and Bases Answer Key WORKSHEET 2 1) C 2) D 3) A 4) B 5) B 6) B 7) B 8) A 9) A 10) B 11) C 12) B 13) B 14) D 15) B

Chemistry Lab Equilibrium Practice Test

Chemistry Lab Equilibrium Practice Test Basic Concepts of Equilibrium and Le Chatelier s Principle 1. Which statement is correct about a system at equilibrium? (A) The forward and reverse reactions occur