------ CHAPTER 4 HOMEWORK

1. Read the chapter and review your notes.2. Answer the following questions; solve the following problems - remember answers withoutsupporting work will not receive credit.

I. Show how each of the following strong electrolytes dissociates upon dissolving in water:

(a) NaBr ~7 Net -r (Mp) .+ 15,.. -Cd';)

1\1,1 J.+- ((Lee l·f- oJ c1 -(~)(b) MgCb

2. Calculate the molarity of each of the following solutions.

(a) A 5.623g sample ofNaHC03 is dissolved in enough water to make a 250.0 mL solution.

; dSOO t,

(b) A 184.6 mg sample ofK2Cr207 is dissolved in enough water to make a 500.0 mL solution.

. soo L O.()OIJ Sqqd;-~

= [. d S oS ')( 10-3f'1 1"

OVER

HfIl03(c) A O.l025g sample of copper metal is dissolved in 35.0 mL of concentratedOsc iORSand thenwater is added to make a total volume of200.0 mL. Calculate the molarity of the Cu2+ ions.

letA .2-+).:: C:.l /0 as~('~{ l"tv! c't,01.000 L ~ 3, ~Sc, &t.

J, 0 0 8'0 ~({S ICoI

; t~.o~s 1< I03~

3. Calculate the concentration of all ions present in each of the following solutions of strongelectrolytes.

;. lO.30~1 I

'iA~.1+ t-- 3 SO<j <l-(d) 2.0 x 10-3 M Ab(S04)3 A~;l.(SO\.(),3;; d.

(A131-J .s: ".OOd lVl ~ A-(\(SO,J3 \ Jon •.i ~:14- _

I L \ /..,r-{ M~(SOu)~ (6,0040 M 1

,001. ""~ 4f, (so" }3 i3",~ Sb./-I L I ••.,,.{l Mz (S04)3 :: '(0. 00 ttOf\11

-- -_. __ ...- .- ... - ------ ----------~----------- ------------~------

4. Calculate the volume of a 0.100 M solution ofNaHC03 that contains 0.350 g ofNaHC03.

z: 0, 0 <f "d 7 S 17

.: ~.O(/l6 L :: L/I. ~nl L ]

5. Describe how you would prepare 2.00 L of 0.250 M NaOH from solid NaOH.el. 00 L rJlA 0 1-4 c;;J SO/YI.~Altd2 f.-/ ,,1. q 19 {VIlO 11

jJo.OI-l: r t, Imr-tJtJP..Ol1 == /tf,qS4C(J~ OlO,~

I?1cLU .:)0, Q9 tJtLO~ L:" a. 01.00 :'I>,(){;.t~1U,tL(~rJ CLrv-.C~ ../f11 (",-d,-:l.t-n1-iY~~).::tdflf /)'11-CLlJ 1,<.;JA. d~Qt,-lU 'Ha a,

6. Describe how you would prepare 1.00 L of 0.500 M HCl from a concentrated (12 M) stocksolution. f"l, \/, "" l"lL\{ 'L

(Ia!"l) <l , ;: (.~()O\'1)(1.00L)

,\'1 -: 0, OLI 11 L -:: LfI.lI'HL

4:1JJ (l L00 L 'v'i:~V"'~~ /~<vk I~·· .tA-'tt-y. J.d dL.t:1U .t\,~.(. '; add •../1. 7 In L

.r6 Ia fI1 I-Ie.J) fn/-iL d(.iu.-:&~ ~ fiu mw.jc: 071 At f&~J:,'.7. A solution is prepared by dissolving 10.8 g of ammonium sulfate in enough water to make a100.0 mL stock solution. A 10.00 mL sample of this stock solution is added to 50.00 mL ofwater. Calculate the concentrations of ammonium ions and sulfate ions in the final solution.

(~1-\4)a .so, (S) -') d,j \-llj+ (~) ,+ ,sOq ,;/-(~)

lCiJl-1lj)aSOIj J ~ 10,85 (tJHtl)J,SOq It"'.,..r (tJU<j):t.SCCj ':.100L. l~cl.137Lj

: 811 iVl.J (A.JH<t), SOt(} ,ole LI L.. i

, 0 (J $- n '11~J .00 ¥ il t1'H'..fs:

•Ij I Li •0 S L , oc:, L

= 0, oof 17

= 1'3l;M,J.(~I-l\()2..s(~Wl.{Aali(-t _ "

I . A (. III ) '''I - d. 7 d f\')I L >11\1"{ I\J /14 'l ",elf

r SO L -) ,.. \. 3In••.o-R (kJ \iLlh SO lj t Ij.••• ...t SOll2--, _ .L '1. ., . i ,..p (All-) ) SO - Ii 3(.{l-l

8. When the following ~5rutions are mi~~d toget~ef, wHat precipitate (if any) will form?

(a) BaCh (aq) and Na2S04 (aq)f~tl .so y

(b) Pb(N03)2 (aq) and KCl (aq)

Pb elL(c) K2S (aq) and Ni(N03h (aq)

~liSOVER

9. Write complete, balanced molecular equations and net ionic equations for the reaction, if any,which occurs when aqueous solutions of the following are mixed:

(a) silver nitrate and barium chloride.J Aj /JOg (~) 1"1'3~C~~~) -7 ;) -j C1 (S) + /34. (AiO?,) J{~)

0) _4j t- ({Lib i + J d -(WV) .-"7 ~ ~ d rs)

f\~1- CCi;"" + c1 --(~~) --, .6 eP ts )

(b) iron (II) sulfate and potassium sulfideFe Soli (ac

b' 4- /(a s(~) -"7 h S (S) f ~ SOt{ (tt.zJ)

\' 'J-+- S ,;- r" o,- e. (C'-]) 4-- {(.~)-'7 r-e,,) (S J

(c) sodium hydroxide and potassium sulfate~ ,J~(5 H (~) +- /(a ~q (~) -"7 ~ ;(01-/ (~).J. AIa:j. SOq (Ct~))

NO REJ.}e77oAi

(d) dimercury (0 nitrate and calcium chloride

IIj:;l (Al03)a (~) ~ (i del (~) -, fa.. (AlO,1)a. (tiJ) + 16,} f!JL (J)

I-t1a .u: (,) of d C1 ~~) -? Iff;; a: (S)

~'-

10. What mass of solid aluminum hydroxide is produced when 50.0 mL of a 0.200 M solution ofAI(N03)3 is added to 200.0 mL of 0.1 00 M KOH?

A~ (I\.IOa)3 CllfD) +' 31(OIl(o..~) -:"7 ,41(611}3 (5) of .3 KAi03 (Ci)

c 050L ,a2()Oln~ ~A1(IJ03)3 /",,j 4UOM)3 7 'i- .01,,9 .4..e(OH)~~q A~ (O(~)3 =

-.J IL ,~~ A~(fJO'3)3 I'h~ 4~(oHh = 0,780/<1

iL

----- -------- ------------------ ---------------------- ------------------------------- -- -- -- -----------

11. Determine the mass, in grams, of sodium carbonate (Na2C03) required to completely react---' with 25.0 mL of 0.155 M nitric acid (HN03).

Na2C03 (aq) + 2 HN03 (aq) -;. 2 NaN03 (aq) + C02 (g) + H20 (I)

j Ma.d

{Os '> () r OQ~jL (-IA.lO.3 • f SS'lI\J HIJ03 IM.~etJaa C03

I L HIJO:'.! -llnr-f HAJOa;0:5. Q1,s JJ42 CC':3

1i>J.-(! JQz CC,3

12. Calculate the mass of carbon dioxide produced when 75.0 mL of 0.350 M HCI reacts withexcess Na2C03.

Na2C03 (s) + 2 HCI (aq) -;. 2 NaCI (aq) + H20 (I) + CO2 (g)

c 3S0 1V\c-i 4cJI L f.-JC1

/''I1.-f CO:;oJIn.,f 1-1C1

41{.01J CO;t/l1lrf [(,.1:;.

13. You can dissolve an aluminum soft drink can in an aqueous base such as potassiumhydroxide:

2 AI (s) + 2 KOH (aq) + 6 H20 (I) -;. 2 KAI(OH)4 (aq) + 3 H2 (g)

If you place 2.05g of aluminum in a beaker with 185 mL of 1.35 M KOH, will any aluminumremain? What mass, in grams, of KAI(OH)4 is produced?

~.0.\, Il ~ I.'.O~_;ld m) "AI(O~), 13qJJS kANOII),_3 k (~~(O\-Ptj :: ac: q rs se C) ''>1) A 1 /,j/J,-i IC4i (Oi-t)4-

:: 10'.)j

I L lc::::.oH

• 185 L

'"' 33, SJ

A~ 10 -iiu ~ AlMta,.i >Qt"'d .to.;)} ok (J!)~tiif; ,tL""d-

OVER

14. How many grams of silver chloride can be prepared by the reaction of 100.0 mL of 0.200 Msilver nitrate with 100.0 mL of 0.150 M calcium chloride? Calculate the concentration of each ionremaining in solution after the precipitation reaction is complete.

~ Aj NO~(~) + & ClOJ (~l -";> CJ Aj d r s) + GL (AJ03)a (~)

A.5+ ('1) + Cl- (~i) -~ .4j CJU)

~9 tjCQ .100 L::

iL

~Astf .: .IOOL=

~[A5') = ¢MJ

• ioot, ./SO 1l"A ~CitIL

• .::looL

• 100 L

Iml~ ~1J(h

, i(DO LJ ' ISO~l1,.f CaUL J,~ e~-I I I t, im&-( Ca.C1 Z--

il-:; L(9, I 00 fYl 4

= Q,030mu-f

:: .I~O L

[c.r J REM41tJ I,J& ::.OIOW\,~

. aoo L= \ 0 t OS 0 f\1 }

------- -- ---

15. Determine the volume of 0.150 M HN03 required to neutralize 50.00 mL of 0.200 M NaOH.

H+C6t.i + OH-(~) -7 Holl (1)b

Q, 0 SO L.: iLIL

16. Determine the volume of 0.0200 M calcium hydroxide )8"required to neutralize 35.00 mL of0.0500 M nitric acid?C:\.(OHL. (u..c"l +. cJ. l-ItJOa (ad -'7 Ct (A104)J {(lJ,j)'f Q 1/01-/(£)

vOl

l (h(OI~)J;:' D.03S0oL .().s('l()m~ H"J03 Im...f Ct (0/·0.,)

i L drnJ l/tJ03

iL

.' O;;JoO mvR d:l (0 I~)J.

z:

17. Assign oxidation states to each of the atoms in the following ions/compounds:

(a) Cr(OHk CI- ~ 31 0; ol- If: /+

Sf't' o:-J

II: -1/ CJ: -/

OVER

---------------

18. Balance the following oxidation-reduction reactions in an acidic solution:

(a) V02+ (aq) + Zn (s) -+ V02+ (aq) + Zn2+ (aq)

e- t .J I-/-+'r voJ f ~ V () .a+ t 11')' 0In -"7 l:n i# r c2e-

- - -- - -~-1

,J e. - + ~ Hi t- .:J '\ID~ -+ +- c:l \/0 t"J I-Ia.0

(b) Cr20l· (aq) + Fe2+(aq) -+ Cr3+ (aq) + Fe3+ (aq)

a-le e - + '4 H-t .•. Cr20 1 .-'7 ~ C r- j-+ f 7 l-lo. 03-t

Fe + e -- - -

c: 14 t\-t +.;)- .,;)C. 3f

7~O+ CiJ 01-"7 +-

(; ~ olf- -'1& r; S+ -4- /t;e-

.~

.~-- ..--- .. _ ..._---

19. Balance the following oxidation-reduction reactions in a basic solution:

(a) Cr042- (aq) + S032- (aq) ~ Cr(OH)3 (s) + S042- (aq)

3 e - +- .$ \-\+ -I- C,... 0 I.j d - -'7 Cr- (0 H) 3 + /-Ii)0 ( .:J )

l~ ~ 0 + S C}z,~ - --; SO\{ 01.- + d- H -If- de. - ( s )

- - - -- - --It .e. - t- 10 14-t 1- d Cr 0

4a- -7 .;2 C.- (0 H)3 of a 1-/')' 0

;3 148-0 t 3 SO/- -7 .3 JOII,J.- + f.e 100ft t: (p e -

(b) Ni02 (s) + Zn (s) ~ Ni(OH)2 (s) + Zn(OH)2 (s)

,J Ha 0 + ll) .-'7 In COli).;! -I d Hi T ,J. e -

c1e.- + Ol/-li"t- J(.'Oa -'7 Ai; (o/f)J.

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OVER