Ms. Moses CSEC Chemistry 2017[2484]

CSEC CHEMISTRY MARK SCHEME FOR SCHOOL B ASED ASSESSMENT ASSESSMENT SCHOOL

:

ST. LUCIA SEVENTH DAY ADVENTIST AC ADEMY

CENTRE NO.

:

140004

TE ACHER

:

MS.MOSES

:

2017

 YEAR OF EXAM

Lab  Number 

Curriculum Unit

1

Statics

"

Thermal energy

%

&ooke's La(

)

*as La(s

, /

-ynamics !adioactivity

0 2

Thermal energy Simp imple 3endulum

4

Simp imple 3e 3endulum

15 11 1"

agnetism and 6lectromagnetism Thermal 3hysics !efraction

1% 1) 1,

-ynamics 6lectricity 6lectricity

1/

Lab Aim YEAR ONE 2015-2016 To determine the centre of gravity of an irregularly shaped lamina To determine th the sp specific heat capacity of copper using the method of mi#tures To determine the relationship bet(een the force applied to an e#tensible spring and its e#tension To investigate the relationship bet(een volume and pressure of a gas+ To find the (eight of a ruler using the principle of moments+ To simulate radioactive decay using coins+ YEAR TWO 2016-2017

To observe observe that (ater is a poor conductor of heat+ To determi rmine (hether the period of a simple pendulum is  proportional to the the number of paperclips of (hich (hich it is made+ To find th the va value fo for gr gravitational fi field st strength. g. g. us using a simple pendulum+ To determine determi ne the magnetic field pattern around different arrangements of t(o magnets. using iron filings

Skill Assessed O!!  A$ O!!  O!!  A$. O!!    O!!  O!!  

To find find the latent heat of fusion of ice+ To investigate investigate the refraction of light passing through a rectangular glass block 

A$ 

To measure average human po(er (hen (alking and running To (ire a three pin plug To determine (hether the current is the same every(here in a series circuit and the voltage is the same across each branch in a voltage circuit

A$.  

3-

Lab # 1- Skill # 1 Observation/Recording/Reporting (O/R/R) Aim: To determine !ic! s"bstances are acids or bases Sc!eme tem Aim: To determine !ic! s"bstances are acids or bases $et!od a) Logical Sequence b) Language (past tense, no pronouns)

Mark 1

1 2

Tables a) Title in caps

2

b) Correct table headings

1

c) Neatly constructed and coplete

1

Observations a) !riginal and "nal colour o# litus paper stated

1

b) Correct colour change (i# none$no %isible or obser%able colour change) TOTAL

1

1%

Lab # &- Skill # ' $anip"lation and $eas"rement ($$) Aim: To separate a mit"re o* sodi"m c!loride and calci"m carbonate Sc!eme tem +"nsen +"rner a) &ir hole closed

$ark   1

b) Light atch be#ore turning on gas

1

c) &d'ust to nonluinous ae

1

,iltration a) *roper #olding o# "lter paper

2

b) +ilter paper oistened #or proper sealing

1

c) Not "lled to edge o# "lter paper

1

d) Miture poured along glass rod

1

Total



Lab #' . Skill #1 Observation/Recording/Reporting (O/R/R) Aim: To separate t!e components o* !lorop!0ll "sing paper c!romatograp!0 Sc!eme tem $ark   Apparat"s a) -ra.ing  neat, accurately labelled $et!od

2

a) Logical sequence (ust include all steps

1

b) Language (past tense, no pronouns)

2

Observations/Res"lts (labelled) a) !riginal colour o# chlorophyll (green)

1

b) Nuber o# coponents (at least t.o)

2

c) Color o# coponents

1

d) *oint o# origin and end point identi"ed

1

e) Title o# results

1

Total

11 (%21

Lab #3 Observation/Recording/Reporting (O/R/R) Aim: To determine t!e t0pe o* bonding in "nknon s"bstances A and + (A4sodi"m c!loride5 +4nap!t!alene) Sc!eme tem $ark   Test 1

Observations /hite, crystalline solid

0

2

/hite, crystalline solid

0

0

2



-issol%ed in .ater #oring transparent, colourless solution  does not dissol%e

1

3

& does not dissol%e

1

4

 dissol%ed #oring colourless solid

2

5

No %isible change6did not elt

1

7

Solid con%erted to colourless liquid

2

8

ulb lit up

1

ulb did not light up

1

19

Total

16(%72)

Anal0sis and nterpretation (A) (A4sodi"m c!loride . ionic5 +4 nap!t!alene . simple covalent) n*erences Test

n*erences

$ark

1

& possibly ionic because crystaline

2

2

 possibly ionic because crystalline

2

0

& soluble in .ater, possible ionic

2



 insoluble in .ater, possibly co%alent

2

3

& insoluble in acetone, possibly ionic

2

4

 soluble in acetone, possibly co%alent

2

5

& high elting point, possible ionic

2

7

 lo. elting point, siple co%alent

2

8

& conducts electricity in .ater, possible ionic 19  does not conduct electricity in .ater, possibly siple co%alent oncl"sion

2

:onic crystals :onic bonding ;igh elting point as a result o# strong

1 1 1

&

2

 

ionic bonds Conducts because contains #ree ions Siple olecular Co%alent bonding Lo. elting point because o# .eak %an der /aals #orces -oes not conduct, contains no #ree ions or consists o# olecules Total



1 1 1 1

1

&2 (%'37)

Lab #7- Skill #& Anal0sis and nterpretation (A) Aim: To determine t!e concentration o* a sol"tion o* sodi"m !0droide "sing standard sol"tion o* !0droc!loric acid b0 titration Sc!eme tem $ark   (i)

&%erage %olue o# ;Cl used, no ark i# calculated using inaccurate %olues (:# .ithin < 9=1c0 o# each other gi%e 2 arks i# .ithin 9=2 c0 o# each other gi%e 1 ark) (ii) nuber o# oles in 19 c0 ;Cl (iii) equation #or reaction, correct state sybols

2

2 1

(i%) correct ole ratio

1

(%)

1

nuber o# oles o# Na!; in a%erage %olue

(%i) concentration o# Na!; in ol d0 (%ii) concentration o# Na!; in g d0 (subtract 1 ark i# unit issing or incorrect) TOTAL

2 2

11(%2%2)

$anip"lation and $eas"rement ($$) +"rette a) >ertical

1

b) No air bubbles

1

c) ?ead eniscus at eye le%el

1

d) &ccuracy o# readings

1

e) ?eo%e #unnel be#ore titrating

1

#) Correct positioning o# "ngers around stopcock

1

g) Constant s.irling o# ask

1

8ipette ?ead at eye le%el

1

 Tip out o# solution .hen reading otto o# eniscus at calibration ark

TOTAL

1 1

1%

Lab #1&- Skill #& Anal0sis and nterpretation (A) Aim: To determine t!e concentration o* a sol"tion o* Acetic acid "sing standard sol"tion o* 9aO! b0 titration Sc!eme tem $ark   (i)

Saple a%erage %olue o# &cetic acid used, no ark i# calculated using inaccurate %olues (:# .ithin < 9=1c0 o# each other gi%e 2 arks i# .ithin 9=2 c0 o# each other gi%e 1 ark) (ii) nuber o# oles in selected %olue o# Na!; (iii) equation #or reaction, correct state sybols (i%) correct ole ratio (%)

nuber o# oles o# &cetic acid in a%erage %olue (%i) concentration o# &cetic acid in ol d0

2

2 1 1 1 2

(%ii) concentration o# acetic acid in g d0 (subtract 1 ark i# unit issing or incorrect) TOTAL

2

11(%2%2)

Lab #8 Title: Organic Ce!i"tr: Al$ane" an% Al$ene"

7a8 '()te"i" 9 7b8 Ai!9 7c8 A((arat*" an% &aterial"  7All:". Some :18 7d8 &et)%

&ar$  1 1 2

7i8 ;easible < variables manipulated to achieve conclusive results 7ii8 (ritten in present tense 7e8 E+(ecte% re"*lt"

2 1

7i8 Appropriate according to hypothesis 7ii8 controlled =ariable 7iii8 manipulated variable

2 1 1

7f8 ,reca*ti)n".)*rce" )/ Err)r A""*!(ti)n" an rea")nable

1 12

Lab #

Anal0sis and nterpretation Aim: To determine t!e !eat o* sol"tion o* copper () s"lp!ate Sc!eme tem

$ark  

alc"lations a) ;eat change .ith dissol%ing 09g b) ;eat o# solution

c)

CuSO4(s)

 ;eat change negati%e  ;eat is gi%en o@ there#ore products ha%e less energy than reactants (ii) Anergy pro"le #or eotheric reaction  &es correctly naed  Correct shape (iii) Sources o# errors  energy lost to environment/thermometer/stirring rod or container (any two 1 mark)  Incomplete transfer of solid   ssumptions! 1 cm" solution has the same mass as 1 cm " of water Specific heat capacity of solution is the same as that of water TOTAL •

•

2 1 1 2 1 1 1 1 1 1

1&

$anip"lation and $eas"rement ($$) $eas"ring 0linder a) +lat sur#ace

1

b) ?ead at eye le%el

1

c) ?ead botto o# eniscus

1

T!ermometer a) +ully iersed bulb

1

b) Stir continuously

1

c) ?ead at eye le%el

1

d) &ccurate reading

1

e) -o not allo. bulb to touch sides o# cup

1

Solid a) Coplete trans#er o# solid

TOTAL

1

2(111)

Lab #6 - Skill #3 8lanning and ;esigning (8;) Aim: To determine !et!er A"nt Sianna::), potassiu dichroate (>:), potassiu iodide, iron(::) sulphate, sodiu hydroide) at least three :>= anipulated %ariable  0 di@erent saples >pected res"lts

2

&ppropriate colour change according to hypothesis

1

1

 Table .ith results

1

No colour change #or solution C (neither)

1

*recautions6Sources o# Arror (any reasonable)

1

TOTAL

1

Lab # 1- Skill # 3 8lanning and ;esigning (8;) Aim: To determine !et!er t!e energ0 val"e o* an alco!ol is related to t!e n"mber o* carbon atoms it contains% Sc!eme tem $ark   =0pot!esis  Anergy %alue o# alcohol increases6decreases as the nuber o# carbons increases6decreases Aim  To deterine .hether Anergy %alue o# alcohol :ncreases6decreases as the nuber o# carbons increases6decreases= Apparat"s and $aterials (all$2, soe$1) $et!od

1

1

2

a= +easible

2

b= Controlled %ariable

2

c= Manipulated %ariable 0 di@erent alcohols containing di@erent nubers o# carbon >pected res"lts &ppropriate according to hypothesis i=e ;ighest carbon nuber $ highest energy and Lo.est carbon nuber $ sallest energy, or %ice %ersa *recautions6Sources o# Arror (any reasonable)

Total

1

2 1

1&

Lab #7- Skill #& Anal0sis and nterpretation (A) Aim: To determine t!e concentration o* t!ree samples o*  vinegar "sing a standard sol"tion o* !0droc!loric acid b0 titration Sc!eme tem $ark   &%erage %olues o# %inegar used, no ark i# calculated using inaccurate %olues (:# .ithin < 9=1c 0 o# each other gi%e 2 arks i# .ithin 9=2 c 0 o# each other gi%e 1 ark) nuber o# oles in 19 c0 ;Cl equation #or reaction, correct state sybols

2 1

correct ole ratio

1

nuber o# oles o# Na!; in a%erage %olue

1

concentration o# Na!; in ol d0

2

concentration o# Na!; in g d0 (subtract 1 ark i# unit issing or incorrect) TOTAL

2

2

11(%2%2)

$anip"lation and $eas"rement ($$) +"rette a) >ertical

1

b) No air bubbles

1

c) ?ead eniscus at eye le%el

1

d) &ccuracy o# readings

1

e) ?eo%e #unnel be#ore titrating

1

#) Correct positioning o# "ngers around stopcock

1

g) Constant s.irling o# ask

1

8ipette ?ead at eye le%el  Tip out o# solution .hen reading otto o# eniscus at calibration ark

1 1 1

TOTAL

1%

Lab # - Skill #1 Observation/Recording/Reporting (O/R/R) Aim: to determine t!e melting point o nap!t!alene Sc!eme tem

$ark  

Recording Table a= &ppropriate title present in caps and underlined b= Correct table headings

2 1

c= Neatly constructed

1

,ormat d= Lab report in orderI title ai apparatus  ethod 2  obser%ations6 results  discussion  conclusion6reection Observations/ Res"lts e= &ppropriate obser%ations

Total

4

1&