CH Practice Exam #3 -

Transcription

1 CH Practice Exam # - Name: Score: Part I (~ points each) Multiple Choice - Choose the best answer and place the letter corresponding to the answer in the space provided AND on the Scantron form. 1. Identify the type of solid for gold. A) metallic atomic solid B) ionic solid C) nonbonding atomic solid D) molecular solid E) network atomic solid. Identify the type of solid for argon. A) metallic atomic solid B) ionic solid C) nonbonding atomic solid D) molecular solid E) network atomic solid. Give the coordination number for a body-centered cubic cell. A) 0 B) 6 C) 8 D) 10 E) 1. Name the following: [Pt(HO)F]Br A) tetraaquadifluoroplatinum(iv) bromide B) tetraaquadibromodifluoroplatinate C) platinum(ii)bromide D) platinum(iii)tetraaquadifluorobromide E) platinum (II) dibromodifluorotetrahydride 5. Choose the chemical formula for diaquadicarbonylzinc tetrabromopalladate (IV). A) [PdZn(HO)(CO)]Br B) [Zn(HO)(CO)][PdBr] C) [Pd(HO)][Zn(CO)]Br D) [Pd(HO)][Zn(CO)]Br E) [Zn(HO)(CO)][PdBr]

2 6. For the following balanced equation, determine the rate of reaction with respect to [H]. N(g) + H(g) NH(g) A) Rate = + Δ[H] B) Rate = - 1 Δt C) Rate = + 1 Δ[H] D) Rate = - Δt 1 1 Δ[H] Δt Δ[H] Δt 7. Give the characteristic of a first order reaction having only one reactant. A) The rate of the reaction is not proportional to the concentration of the reactant. B) The rate of the reaction is proportional to the square of the concentration of the reactant. C) The rate of the reaction is proportional to the square root of the concentration of the reactant. D) The rate of the reaction is proportional to the natural logarithm of the concentration of the reactant. E) The rate of the reaction is directly proportional to the concentration of the reactant 8. What is the overall order of the following reaction, given the rate law? X + Y Z Rate = k[x][y] A) rd order B) 5th order C) nd order D) 1st order E) 6th order 9. What are the units of k in the following rate law? Rate = k[x][y]1/ A) M/s B) M -1 s -1 C) M 1/ s -1 D) M -1/ s -1 E) M -1 s -1/ 10. Which of the following statements is FALSE? A) The half life of a zero order reaction is dependent on concentration. B) The half life of a second order reaction is not dependent on concentration. C) The rate of second order reactions is dependent on concentration. D) The rate of a first order reaction is dependent on concentraion. E) None of the statements are FALSE.

3 11. The half life for the decay of radium is 160 years. What is the rate constant for this firstorder process? A) yr -1 B) yr -1 C). 10- y -1 D) y -1 E) yr Identify an heterogeneous catalyst. A) CFCs with ozone B) solid Pd in H gas C) KI dissolved in HO D) HSO with concentrated HCl E) HPO with an alcohol 1. Given the following rate law, how does the rate of reaction change if the concentration of Y is doubled? Rate = k [X][Y] A) The rate of reaction will increase by a factor of. B) The rate of reaction will increase by a factor of. C) The rate of reaction will increase by a factor of 5. D) The rate of reaction will decrease by a factor of. E) The rate of reaction will remain unchanged. 1. How many half-lives are required for the concentration of reactant to decrease to 1.5% of its original value? A) B) C).5 D).75 E) The combustion of ethylene proceeds by the reaction C H (g) + O (g) CO (g) + H O(g) When the rate of disappearance of O is 0.8 M s-1, the rate of appearance of CO is M s-1. A) 0.19 B) 0.09 C) 0.8 D) 0. E) 0.56

4 16. Determine the identity of the daughter nuclide from the alpha decay of 86 Rn. A) 18 Po 8 6 B) 88 Ra C) 90Th D) 86 Rn 1 E) 85 At 17. Determine the identity of the daughter nuclide from the electron capture by A) 55 Co 7 B) 55 Mn 5 C) 56 Co 7 D) 5 Mn 5 E) 51 Cr 55 Fe The following reaction represents what nuclear process? Pb -1 e + Bi 8 A) beta emission B) positron emission C) gamma emission D) electron capture 19. Which of the following nuclides is most likely to decay via positron emission? A) Cs-17 B) I-11 C) Al- D) K- E) N-1

5 Part II (~8 points each) - Show all of your calculations for full credit. 1. Aluminum crystallizes in a face centered cubic structure with an edge length of r. The atomic radius of aluminum is 1 pm. What is the density of aluminum. What is the equilibrium concentration of Co+ in s solution that is initially M Co(NO) and M OH- after the following equilibria is established: Co + (aq) + (OH)- (aq) Co(OH) - K f = 5.0 x Determine the rate law and the value of k for the following reaction using the data provided. SO8 (aq) + I (aq) SO (g) + I (aq) [SO8 ]i (M) [I ]i (M) Initial Rate (M-1s-1)

6 . The first-order decomposition of NO at 1000 K has a rate constant of 0.76 s-1. If the initial concentration of NO is 10.9 M, what is the concentration of NO after 9.6 s? 5. The first-order rearrangement of CHNC is measured to have a rate constant of.61 x s-1 at 98 K and a rate constant of s-1 at 5 K. Determine the activation energy for this reaction. 6. The age of an ancient tree trunk is estimated using radiocarbon dating. If the trunk has a C-1 decay rate that is % of what it is in living plants, how old is the trunk? The half-life of C-1 is 570 years.

7 Ionic Solubility Chart Soluble Exceptions NO None CHCOO None Cl Ag +,Hg +,Pb + Br Ag +,Hg +,Pb + I Ag +,Hg +,Pb + SO Sr +,Ba +,Hg +,Pb + Insoluble Exceptions S NH +, alkali metal cations, Ca +, Sr +,Ba + CO NH +,alkalimetalcations PO NH +,alkalimetalcations OH NH +, alkali metal cations, Ca +, Sr +,Ba + + Polyatomic Ions NH Ammonium BrO Bromate CN Cyanide CHO Acetate (CH COO ) ClO Perchlorate ClO Chlorate ClO Chlorite ClO Hypochlorite IO Iodate MnO Permanganate NO Nitrate NO Nitrite OH Hydroxide HCO Hydrogen carbonate HSO Hydrogen sulfate SCN Thiocyanate CO Carbonate Cr O Dichromate 7 CrO Chromate SO Sulfate SO Sulfite PO Phosphate Constants Boltzmann s constant kb = m kg s K 1 Coulomb s constant kc =1/( 0) = J m/c Avogadro s number NA = mol Faraday s constant F = C/mol Planck s constant h = J s Ideal gas constants R =0.081 (L atm)/(mol K) R =8.1 J/(mol K) 1 1

8 Eºcell = Eºred + Eºoxid Eºcell = Eºcathodee - Eºanode 1.00 A = 1 C/sec KINETICS ln[n]t = -kt + ln[n]0 ln[n]t - ln[n]0 = -kt [N]t = [N]0 x e -kt Rate Laws Integrated Rate Laws Half-life formula Rate = k[a] 0 = k [A] = -kt + [A] 0 graph of [A] vs. Rate = k[a] ln[a] = -kt + ln[a] 0 graph ln[a] vs. time Rate = k[a] 1/[A] = kt + 1/[A] 0 t½ = [A0]/k t½ =0.69/k t½= 1/(k[A0])