Ionic Compounds, Formulas, and Reactions 165

actice Exercises

ultiple-Choice: I the first four problems below, one or more of the following responses will apply;

response may be used more than once or not at all in these questions.1. ammonium ion 4. Which compound will be

II. calcium ion insoluble?III. bromide ionIV: iron (III)V. phosphate ion

1. Which of these carries a singlenegative charge?

(A) I and V(B) III and I(C) II and III(D) III and IV(E) IV and V

(A) I(B) II(C) III(D) N(E) V

5. Which of the following compoundsis soluble?

-. Which pair of these will form acompound?

(A) I and II(B) II and IV(C) III and V(D) I and IV(E) II and V

(A) MgC03(B) Al(OH)3(C) Cr2S3(D) K2Cr04(E) NiS03

6. Which of the following compoundsis insoluble?

(A) 1(B) 2(C) 4(D) 6(E) 9

(A) Ca(OHh(B) Fe2S3(C) Na2C03(D) H2S03(E) AuC13

7. Which of the following is thepermanganate ion?

3. How many different compoundscan be made from these ions?

(A) Cl04(B) PO~-(C) Mn02(D) sot(E) Mn04

166 AP Chemistry

S. When ammonium oxalate,(NH4)2C204' is dissolved in water,the ions formed are

(A) 2N3-(aq) + SH+(aq) +2C4+(aq) + 402

- (aq)(B) (NH4)2+(aq) + C20~-(aq)

(C) 2NH~(aq) + C20~- (aq)(D) NH~+(aq) + C20~-(aq)

(E) 2NH~(aq) + 2CO~ (aq)

9. The correct name for Fe(N03)3 is

(A) iron nitrite(B) iron (II) nitrate(C) ferrous nitroxide(D) iron(III) sulfate(E) iron (III) nitrate

10. When the combustion reaction forbenzene, C6H6, is properlybalanced with the smallest whole-number coefficients, the sum of thecoefficients is

(A) 15(B) 12(C) 35(D) 17.5(E) 12

11. The potassium ion is isoelectronicto which noble gas?

(A) He(B) Ne(C) Ar(D) Kr(E) Xe

12. Which two atoms will formisoelectronic ions?

(A) CI and Na(B) CI and F(C) Na and F(D) 5 and Br(E) Fe and Ca

13. What is the formula for an ioniccompound formed from aluminumand chlorine?

(A) AlCl(B) Al3Cl(C)Al3Cl3(D) AlCl3(E) Al2Cl3

14. The electronic configuration2 2 6 2 6 d15 25 2p 35 3p correspon s to

the electronic configuration of

(A) 52-

(B) Ca2+

(C) cr(D) r(E) all of these

15. Which of the following is NOTcorrectly named?

(A) cr(B) ClO-(C) CIOi(D) ClO~(E) CIO~

chloride ionhypochlorite ionperchlorate ionchlorous ionchlorate ion

16. Which of the following is NOT acorrect chemical formula?

(A) 5rBr2(B) Ca203

(C) Mg3N2

(D) Na25(E) AlI3

17. Which of the following is a correctformula?

(A) NH4503(B) CaC2H302(C) Na2CI04(D) Ba(C03)2(E) KH2P04

18. Which of the following is a single-replacement reaction?

(A) sodium chloride with. potassium nitrate

(B) chlorine gas with sodiummetal

(C) aluminum metal withhydrobromic acid

(0) ethanol with oxygen(E) magnesium oxide with sulfur

trioxide

19. Which of the following is NOTtrue of a net ionic equation?

(A) All of the nonreacting(spectator) ions have beencanceled.

(B) It shows the actual reactants inan equation.

(C) It allows the chemist tosubstitute reactants in a logicalmanner.

(0) It is used to determine whichcompounds are insoluble.

(E) It must have the charges aswell as the atoms balanced.

SWER KEY

1. C2. E3.0

4. E5.06. B

7. E8. C9. E

See Appendix 1 for explanations of answers.

Ionic Compounds, Formulas, and Reactions 167

I CHALLENGE I20. What is the balanced molecular

equation when FeCl3(aq) is mixedwith Ba(OH)2(aq)?

(A) Ba(OH)2(aq) + FeC13(aq) ~Fe(OH)2(aq) + BaC13(aq)

(B) 2Ba(OH)2(aq) + 3FeC13(aq)~ 2BaCl2(aq) + 3Fe(OH)3(s)

(C) 3Ba(OH)2(aq) + 2FeC13(aq)~ 3BaC12(s) + 2Fe(OH)3(s)

(0) 3Ba(OH)2(aq) + 2FeC13(aq)~ 3BaC12(aq) + 2Fe(OH)3(s)

(E) Ba(OH)2(aq) + 2FeCl3(aq) ~BaC12(aq) + 2Fe(OH)3(s)

I CHALLENGE I21. What is the net ionic equation for

the following reaction that takesplace in aqueous solution?

CrCl3 + Pb(N03)2 ~

PbC12 + Cr(N03)2

(A) Cr2+(aq) + Pb2\aq) ~ CrPb(s)(B) Cr3(aq) + 3N03(aq) ~

Cr(N03)3(s)(C) Pb2+(aq) + 2Cnaq) ~

PbCl2(s)(0) Pb(N03)(s) + 2Cnaq) ~

PbC12(s) + 2 N03(aq)(E) 2CrCl3(s) + 3Pb2+(aq) ~

2Cr3+(aq) + 3PbC12(s)

10. C11. C12. C

16. B17. E18. C

13. 014. E15. 0

19. 020.021. C