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Published : Tuesday, March 27, 2012
Reading/s : 11
Origin : dentonisd.org
Number of pages: 6
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AP Chemistry Test (Chapter 4)Please use the answer sheet!! Multiple Choice/FIB (50%) Please use the following choices to answer questions 1-6. A) NaNO3C) O2Oil (C D)xHY) E) Sugar(C11H22O12Wax (C) H)xHy) I) Fe3P21) Pleasechooseallsubstances with ionic bonds. 2) Pleasechooseallsubstances with nonpolar covalent bonds 3) Pleasechooseallsubstances with polar covalent bonds. 4) Pleasechooseallsoluble substances. 5) Pleasechooseallsubstances that would dissociate in water. 6) Pleasechooseallsubstances containing both ionic and covalent bonds. 7) Pleasechooseall truestatements.  A)All polar covalent substances dissolve in water.  B)Water is nonpolar covalent.  C)All polar covalent substances dissociate in water.  D)All ionic substances dissolve in water.  E)All ionic substances dissociate in water. 8) Pleasechooseall falsestatements.  A)All nonpolar covalent substances are insoluble in water.  B)Soluble polar covalent substances dissociate in water.  C)Soluble ionic substances dissociate in water.  D)Nonpolar covalent substances dissociate in water.  E)Water is ionic. 9) Pleasechooseall truestatements.  A)Water has slight dipoles.  B)Oil has slight dipoles.  C)Salt has extreme dipoles.  D)N2has slight dipoles.  E)Wax has extreme dipoles.
10) Pleasechooseall falsestatements. A) Atomsin an ionic bond have extreme dipoles because the atoms transfer valence electrons completely. B) Atomsin a nonpolar covalent bond have slight dipoles because the atoms share valence electrons equally. C) Atomsin a polar covalent bond have extreme dipoles because the atoms share valence electrons unequally. D) Atomsin a polar covalent bond have slight dipoles because the atoms share valence electrons equally. E) Atomsin an ionic bond have no dipoles because the atoms transfer valence electrons completely. Please use the following choices to answer questions 11-13.  A)H3PO4H B)2O  C)KOH D)HBr  E)NO2 H)FeCl3  I)PbSO4 J)CuOH 11) Pleasechooseallstrong electrolytes. 12) Pleasechooseallweak electrolytes. 13) Pleasechooseallnonelectrolytes. 14) Pleasechooseall truestatements. A) Solubleionic compounds are strong electrolytes because they dissociate in water to produce ions. B) Solubleionic compounds are strong electrolytes because they dissociate in water to produce neutral atoms.  C)Polar covalent compounds are weak electrolytes because they have slight dipoles. D) Polarcovalent compounds are nonelectrolytes because they dissociate slightly in water to produce some ions.  E)Nonpolar covalent compounds are nonelectrolytes because they have no dipoles. 15) Pleasechooseall falsestatements.  A)Weak acids are weak electrolytes because they dissociate slightly in water.  B)Strong bases are strong electrolytes because they dissociate completely in water.  C)Weak bases are nonelectrolytes because they dissociate slightly in water.  D)Strong acids are weak electrolytes because they dissociate slightly in water. 16) Whichone is precipitous?  A)CuCl2(NH B)4)3PO4 C)NH4Cl D)Cu3PO4
17) Whichone is the formula for the precipitate that forms when aqueous  iron(II) nitrate is added to aqueous sodium carbonate?  A)NaNO3FeCO B)3 C)Na2NO3 D)Fe(CO3)2 E)None of these 18) Whichone would be most appropriate for making 500 ml of a solution?  A)Graduated cylinder and volumetric flask B) Beakerand graduated cylinder C) Beakerand volumetric flask D) Buretand volumetric flask E) Buretand graduated cylinder 19) Whatis the oxidation number of P in Mg2P2O7?  A)+2 B)+7 C) +5D) +8 E) Noneof these 20) Whatis the oxidation number of C in the oxalate ion?  A)+4 B)+6  C)+3 D)+2  E)None of these Please consider the following reaction to answer questions 21-25. – –2+  Br(aq) + MnO4(aq) Br2(l) + Mn(aq) 21) Whatelement is reduced? 22) Whatspecies is the reducing agent? 23) Whatelement loses electrons? 24) Whatspecies is oxidized? 25) Whatelement produces the electrons? Problems and Free Response (60%) Please show all your work for any credit!!3+ 1) A0.4508-g sample of iron is dissolved in a small amount of HNO3to form Feions in solution. Theresulting solution is diluted to a total volume of 500.0 ml.Please calculate the 3+ molarity of the Feions.
2) Howwould you prepare 200.0 ml of a 0.625 M H2SO4solution from a stock solution of 16.0 M? 3) Pleasecalculate the concentration of all ions in a 0.115 M Al2(SO4)3solution. 2+ 4) Alake may be polluted with Pbions. Whatprecipitation reaction might you use to test for 2+ the presence of Pbions? Pleasewrite the complete, balanced reaction. Please consider the following information to answer questions 5-7.  2Cr(ClO3)55 Na +2C2O4 10 NaClO3 +Cr2(C2O4)510.0 ml of 0.222 M Cr(ClO3)5is slowly added to 13.0 ml of 0.111 M Na2C2O4. Achemistry student collects and dries the precipitate.The precipitate has a mass of 0.208 g. 5) Pleaseidentify the limiting and excess reagents. 6) Pleasecalculate the % yield of the precipitate and give a likely source of error to explain the % yield. 7) Pleasecalculate the concentration of the aqueous product after the reaction is complete. 8) An6.912-g impure sample of Al2(CO3)3is titrated with 20.0 ml of 0.544 M HCl until the reaction appears to be complete.What is the mass % Al2(CO3)3in the impure sample?
Al2(CO3)3 +6 HCl 2 AlCl33 H +2CO39) Asolution is 87.0% H2C2O4& has a density of 1.18 g/ml.What is the molarity? 10) A245.3-ml sample of a 0.345 M CaCl2solution is accidentally left on a hot plate overnight. The next morning, the solution is 0.456 M.What volume of water evaporated from the original solution of CaCl2? 11) Whatvolume of 0.344 M Al(NO3)3is necessary to completely react with 28.20 ml of 0.455 M H2C2O4?  2Al(NO3)3 +3 H2C2O4 6 HNO3Al +2(C2O4)312) Pleasedraw a magnified view of NaCl dissolved in water.Be sure to show the NaCl and the water including any dipoles.
AP Chemistry Test (Chapter 4)Name_________________________________ Multiple Choice/FIB (50%) 1) _______________16) _____ 2) _______________17) _____ 3) _______________18) _____ 4) _______________19) _____ 5) _______________20) _____ 6) _______________21) _____ 7) _______________22) _____ 8) _______________23) _____ 9) _______________24) _____ 10) _______________25) _____ 11) _______________ 12) _______________ 13) _______________ 14) _______________ 15) _______________ Problems (60%) 1) Pleaseuse only the front side of each piece of paper. 2) Pleasenumber your problems clearly and consecutively. 3) Pleasestaple your problems to the back of this page in numerical order. 4) Pleasewrite on the paper in the conventional manner. 5) Pleasedo not make a separate list of answers.Record your answer at the end of the work supporting your answer. 6) Pleasecircle/box your answer.
AP Chemistry Test (Chapter 4) Answer Key 1) AI2) CDH 3) E4) AE 5) A6) A 7) A8) BDE 9) AC10) BCDE 11) CDH12) AJ 13) BEI14) A 15) CD16) D 17) B18) C 19) C20) C 21) Mn22) Br–-23) Br24) Br 25) Br 1) 0.01614M 2) 7.81ml stock (concentrated) solution Do it as you oughta’…add the acid to a small amount of watta’ in a beaker.Pour the diluted acid in the beaker into a 200-ml volumetric flask.Add water to the mark. 3+ 2-3) 0.230M Aland 0.345 M SO42+ 2-4) Pb(aq) + SO4(aq) PbSO4(ppt) 5) LR= Na2C2O4and ER = Cr(ClO3)5work must be correct) (all 6) 132%too much mass…ppt was probably still wet 7) 0.125M NaClO38) 6.14% 9) 11.4M(11.4 mol H3PO4/1 L of solution) 10) 60.ml H2O evaporated 11) 23.9ml + — 12) Picturemust show Naand Cldissociated from each other.Partially + H end of water — + molecules surround Cland partially – O end of water surround Na.  Bigpoints off for showing water dissociating…it’s covalent.
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