tyler thomas larkin

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Tyler Thomas November 9,2012 Period 3 lonicvs. Covalent Bonding Lablnvestigation Introduction: Mostatoms need to form chemical bonds to become stable and in doing so,theytend to create an octet.In otherwordsrthey start to forma fu!.lglell of valglle eleglgns. There are two maintypes of chemical bonding, whichrrl,ol'. ,!d corg.!:l!._ lonicbonding normally consists of both arnetaland nonmetal element. In the process.metals lose valence electrons q}-_ I \ \ I (.-\l dueto their low electronegativity enlfgy, or ability to attract electronsrand then become €l\- -r negatively charged cations; whereai nonmetals typically gainelectrons because they contain a high electronegativity and become{a positively charged anion. lonic compounds transfer electrons and laterbecome crystals, whichleads them to onlyconducting electricity when dissociating in water. In contrast, covalent bonds areformedfrom two nonmetal elements. In <-*-.**-* covalent bonds, electrons are shared between bonds. Covalent bonds tend to result in a -*''z'' f'C) molecule structure andneye!:*conduct eleciriiny due to thei|oW}nd++r€3-]nt and t electronegativity. The purpose of this experiment wasto conclude whethereach of the different compound were either ionic or covalent bonds. rr-.. ( ,.. r: l- -.\ \__\_/ * t t.". pus-h

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Page 1: Tyler Thomas Larkin

Tyler Thomas

November 9,2012

Period 3

lonic vs. Covalent Bonding Lab lnvestigation

Introduction:

Most atoms need to form chemical bonds to become stable and in doing so, they tend

to create an octet. In other wordsrthey start to form a fu!.lglell of valglle eleglgns. There are

two main types of chemical bonding, which rr l ,ol ' . , !d corg.!: l ! ._ lonic bonding normally

consists of both arnetal and nonmetal element. In the process.metals lose valence electronsq}-_

I

\

\I

(.-\ ldue to their low electronegativity enlfgy, or abil i ty to attract electronsrand then become

€l\ - - rnegatively charged cations; whereai nonmetals typical ly gain electrons because they contain a

high electronegat iv i ty and become{a posi t ively charged anion. lonic compounds transfer

electrons and later become crystals, which leads them to only conduct ing electr ic i ty when

dissociating in water. In contrast, covalent bonds are formed from two nonmetal elements. In<-*-.**-*

covalent bonds, electrons are shared between bonds. Covalent bonds tend to resul t in a

-* ' 'z ' ' f 'C)

molecule structure and neye!:*conduct eleciriiny due to thei|oW}nd++r€3-]nt and t

electronegativity. The purpose of this experiment was to conclude whether each of the

di f ferent compound were ei ther ionic or covalent bonds.

rr-.. (,..

r: l- -.\\__\_/

*

t t ." .pus-h

Page 2: Tyler Thomas Larkin

Tyler Thomas

November 9,2012

Period 3

Hypotheses:

Table 1: The expected Results of different substances

Procedures:

PART f . Melting Point ond Strength of Bonds

1. Fold aluminum foi l into a square to f i t on the r ing- stand. Place a smal l sample of each of

the four di f ferent compounds on your square of a luminum foi l at the same t ime. Be careful not

to mix them up.

2. Careful ly place the tray on the r ing stand and heat wi th the Bunsen Burner, no longer than

1-2 minutes.

3. lmmediately begin recording your detai led observat ions, keeping track of the order in

which the samples melt . Some samples may not melt , a lso decide which sample have strong

and weak bonds.

4. Al low the square of foi l to cool then wash it .

Part 2. Electr ical ConductivitY

1. Weigh an approximately 0.1- gram sample of each compound in di f ferent sect ions of a wel l

p late (make sure to zero the wel l p late on the balance)

2. Test the dry compound for conductivity with the tester. Record your observations.

3. Add enough drops of d ist i l led water to the wel l to dissolve the compound as best as you

can.

Compounds tobe Tested

ChemicalFormula

Hypothesis 1:lonic or Covalent

Hypothesis 2: Highor Low Melt ingPoint?

Hypothesis 3: Wi l l i tconduct electr icity?

Dist i l led Water Hzo Covalent Low No

SodiumChlor ide

NaCl lonic High Yes

Sucrose C12H 12O11 Covalent Low No

Dextrose CoHrzOo Covalent Low No

Sodium Sulfate NaSOa lonic High Yes

Page 3: Tyler Thomas Larkin

Tyler Thomas

November 9,2012

Period 3

4. Test the solution for conductivity with the tester. Record your observations, and be sure towash the conductivity tester with dist i l led water after every use.

5. Repeat for a l l samples unt i l f in ished.

Results:

Conclusion/Analysis:

After this laboratory, i t was concluded that sodium chloride and sodium sulfate wergjoni.c

compounds, whi le dist i l led water, sucrose, and dextrose were covalent compounds. Al l of the*t.-*- ,*'

in i t ia l hypotheses were correct . From the resul ts, the ionic compounds were those that

conducted electr ic i ty in water and had high melt ing points. However, the covalent compounds

had low melt ing points and did not conduct electr ic i ty. lonic bonds are formed from cat ions (+)*-g"

" ; ; ; ; " they dissolve in water,electr ic i ty is able to f low through the solut ion.

t \

\ and anions (-) fp when they dissol ' . ,

Addit ionally, ionic bonds are very strong because the electrostqtic attractio,n that holds the/--1^ ^.-n[- r:{Lo.]t- I 'n' .o \\r-, .^g, \r?ai,^f ,i(Lt tl* f..p \.'r i^*r V?o,.

:rnic corinoJnds iontain twd elements, 6oth a

r le \ )

^Act. \ \

cat ion and anion together( is s Typical ly ionic compounds contain two elements, b

Table 2: The Results of Testing Five Different Chemicals

Name/Chemical

Formula:

PART I:

Melt ing Point (1-5;

High, Med. Or Low?)

Part l l : Conduct

electricity? (Yes/No)

FINAL CONCLUSION:

lonic or Covalent

Bonds?Dry Dissolved

Disti l led Water/ H2O L N/A No Covalent

Sodium Chlor ide/

NaCl

5 No Yes lonic

Sucrose (sugar)/

CsHrzOo

2 No No Covalent

Dextrose/ CoHrzOo 3 No No Covalent

,Sodium Sulfate/

IKrtoo4 No Yes lonic

metal and nonmetal which wai$ 'e evidence that led to the conclusion that they are ionic

Page 4: Tyler Thomas Larkin

-'7

Tyler Thomas

November 9,2012

Period 3

compounds. When a metal reacts wi th a nonmetal an ionic crystal is produced because the

electrons were t ransferred from the metal to the nonmetal . When ionic crystals dissolve in

water, the cation and anion break apart which al lows them to (nove freely aqd conduct '{ ' )"r ' ' J - i-,

,>._^, t[r\ i'.

electr icity. lonic bonds are able to conduct electr icity because the cation and anion move free ,S.. i l -1,,^ru --.-.--'-.."^

and carry an electric current. \r q. "r-1 , t ' l", :.--*-*--. rp'l). .:-{J .]

However, sucrose, dextrose, and dist i l led water were al l covalent compounds. Covalent i . l ' ) Q..,.(, t ' '^

bonds do not conduct electr ic i ty and have low melt ing points. Covalent bonds contain two

nonmetals, which always have high electronegativity. Nonmetals strongly attract electrons, so

nei therelement loses electrons. Instead the electrons are shared between the bonds. Instead\--_ -------

of forming crystals l ike ionic bonds, covalent bonds create Tl l lgpups of molecules. The

molecule is held together because the posit ive nucleus is attracted to the negat ive electrons

being shared between them. Covalent bonds cannot conduct electr ic i ty l , 1. \]

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Page 5: Tyler Thomas Larkin

It is all about the learning

----'+1-Period:

lonic & Covalent Bonding

6

ReportSection

Criteria Advanced-4 Proficient-3 Basic-2 Below Basic-1

Introduction andHypotheses

The Introduction coversall needed backgroundknowledge clearly andinsightfully andintroduces the purposeof the lab. Hypothesesare presented clearly.

and

uceso lab

The Introductioncovers most of theneeded backgroundknou4edge unclearlyand introduces thepurpose ofthe lab.Hvnotheces are

presented unclearlv.

The Introductioncovers some of theneeded backgroundknowledge poorlyand introduces thepurpose ofthe lab.Hypotheses arepresented poorly.

9q

xq

3&r.

Procedures Methods used in theexperiment ar6\-.

completelv.

'\explalner m srudiown wo{ds and 19what w{donejli

N4ethods used in theawnprimpnt a.-

explained in sludent'sown words andmostly reflect whatwas done in lab.

Methods used in thecvncr imcnt arp

explained in student'sown words andsomewhat reflectwhat was done in lab.

Methods used in theewnarimart a"o

explained in student'sown words andsomewhat reflectwhat was done in labwith other errors-

Results All observations madeauring-tfJiipen\are npatly entered'are npat.ly enterectable\ The table hHead\S that desywhat itp ,9Jz6.

loa

60-80" observationsmade drrr ino fhe

experiment are neatlyentered into a table.The tabie has aheading that describeswhat it contains.

40-60Yo observationsmorlo ,1". i - - t l ' -

evner imenf r .p na.r l ! ,

entered into a tab1e.The tabie has aheading that describeswhat it contains.

Z0-4Ao observationsmade during theexperiment are neatlyentered into a table.The table has aheading that describeswhat it contains.

q

U

of ResultsUse All of t fesu

rncorporexplained theconclusion

60-80"4 ofthe resultsare incorporated arrdevnlained in the

conclusion paragraoh.

40-609/' of the resultsare incorporated andexplained in theconclusion paragraph.

2A-40o4 ofthe resultsare rncorporated andelnlaincd in the

conclusion paragraph.ConceptualUnderstanding ofTypes of Bonding

Response clearlydemonstrates arrinsightful & excellentunderstalding ofbondilg includingionic vs covalent [.pes.

Resporlgg-.-..--demgffitrates h,gqodun$brstanding of ),L. . , ' , /Dopomg. rncluoFsorhe exnianad6n of. .\_:_/,lonlc vs covalent

bond rypes.

Responsedernonstrates anunclearunderstanding ofbonding and onlybasically explainsionic vs covalentfypes.

Response does notdemonstratg anunderstanding ofbonding & does notmention ionic vscovalent bonding.

Use of Vocabularystabie. octeVfullshell. ionic. covalent.share valence e-.transfer valence e-.eiectricitv, crystal.cation. anion. ion.elecirostaticatfraction, molecu-ie.etc.

Response uses ATLEASTSwocabula"r.r*"fl,

"o*Jgtfy no*

thy'list on thb 1\ft to- L- - i i ^thq hst on thF lFlt tohdlp supporrthdir

"lit^uri/" /f /

Response uses 4vocabulary wordscorrectly from the liston the left to helpcrrnnnrt fhcir

explanation

Response uses only 3vocabulary wordscorectly fiom the liston the left to helpqrrnnnrf their

expianation

Response uses 2 orfewer (or useswords incorrectly)vocabular,v wordscorrectly from the iiston the left to helpsr rnnnrt fheir

explanation

o

Format andGrammar-double spaced witilnumbered pages-third person is used-no grammatical errors-subscripts are usedr.r'hen appropriate-repofi sections utilizeheadings-Tahlec and f isrrre<

contair headings u'ithdescripfions.

The conventions to theleft are foilowed withno mistakes

The conventions tothe left are followedwith l-5 mistakes

The conventions to The conventions tothe left are foliowedwith 11-15 mistakes

Overall Grade: t28No Excuses : Andrerv. I arkin@animo. org 63 0 -8 5 4 - 6822