TOTAL 15 - New Zealand Qualifications Authority · ACCa/Msfi five)[e‘M/emA ,‘ncretaéi. 7&3...
Transcript of TOTAL 15 - New Zealand Qualifications Authority · ACCa/Msfi five)[e‘M/emA ,‘ncretaéi. 7&3...
911640
2SUPERVISOR’S USE ONLY
9 11 6 4
© New Zealand Qualifications Authority, 2017. All rights reserved.No part of this publication may be reproduced by any means without the prior permission of the New Zealand Qualifications Authority.
ASSESSOR’S USE ONLY
TOTAL
Level 2 Chemistry, 201791164 Demonstrate understanding of bonding,
structure, properties and energy changes
2.00 p.m. Thursday 16 November 2017 Credits: Five
Achievement Achievement with Merit Achievement with ExcellenceDemonstrate understanding of bonding, structure, properties and energy changes.
Demonstrate in-depth understanding of bonding, structure, properties and energy changes.
Demonstrate comprehensive understanding of bonding, structure, properties and energy changes.
Check that the National Student Number (NSN) on your admission slip is the same as the number at the top of this page.
You should attempt ALL the questions in this booklet.
A periodic table is provided on the Resource Sheet L2–CHEMR.
If you need more room for any answer, use the extra space provided at the back of this booklet and clearly number the question.
Check that this booklet has pages 2 –12 in the correct order and that none of these pages is blank.
YOU MUST HAND THIS BOOKLET TO THE SUPERVISOR AT THE END OF THE EXAMINATION.
Merit
15
QUESTION ONE
(a) When solid calcium chloride. CaC14s). reacts with water. the temperature increases.
Circle the term that best describes this reaction.
Give a reason for your choice.
{teal .45la;
(b) When a person sweats. water is lost from the body by evaporation. This is an endothermicprocess. This evaporation speeds up when a person exercises.
(i)
(ii)
4L6 gnu/709nm”; i3 «set/Q 1c; 757%: Swemfl
lASSESSOR'Sl USE ONLY
ll
endothermic
iybi 72w 9.0v/"vaen/ . Wan; 8/153. v
~§r[my
Explain why the evaporation of water in sweat from the body is endothermic. and whyexercise increases this evaporation..fi
{b adoflafll‘c Aeccwe ii (CSII’AQv/Skn, 722 8flvfm-7MIJ- J (on («Oi/V1 [Ii-v.11 eKe{CISJ1J/ [Umca‘s Ara-W3 Wig/\QK @
ACCa/Msfi five )[e‘M/emA ,‘ncretaéi. 3,955 7&3 SWGML
@7464“j3 C Vafléru/‘f’ , vFcr/IWch/B W’ex”
Draw a labelled enthalpy diagram for the evaporation ot‘water. HZOU").
H20({’) —> H2O(g) ArHO —— 40.7 kJ mol’1 _
—)
Enthalpy
H
Ll\"'\ji yll"
\y, >Reaction proceeds
Chemistry 91164, 2017
3
finfifimeUSE ONLY(iii) Sodium chloride, NaCl, is another compound that is excreted from the body in sweat.
Use your knowledge of structure and bonding to explain the diSSOIVing Process Ofsodium chloride, NaCl, in water.Support your answer with a labelled diagram.
.NaClhjs 7a,,‘W_V,¢m‘,;c_i_ w _Cc91__mfl_rp_o~ma/ _,wa,_.5$ffjds, all"fines/1‘1;j,,\,
, «fa/w:filing/g,newjello“it.ewe/Z“);ems_Ae/q,4,_,/p7_es/z¢Ajms Ill/[37-7w_ Q 7. .. - ?.,625.,,/_dkJig-Olga»; v \\
g? flea, i “x
H1O _ "r‘ 7 Q ,.
weFkflsesiijwfle
5\_______I'VLA’¢N~“Wg. , —.L§__+§7L‘ r'[W ~ \
Chemistry 91164, 2017
4
acts with a metal powder.(e) 'l‘hcrmitc reactions occur when a metal oxide rc-
Thc equations for two thermite reactions are given below:
Reaction 1: F8203(S) + 2A|(S) -> 2Fe(5) + Al203(s)Reaction 2: 3CUO(S) + 2AI(S) —-> 301(3) + A|203(S)
ArH° = —852 kJ mol‘1
ArH° = —1520 kJ mol‘1
1362030), or copper(II)l oxide is reacted withUse calculations to determine which metal oxide, iron(III) oxide,
oxide, Cu0(s), will produce more heat energy when 50.0 g of eaCh metaaluminium powder, Al(.s').
Mvr(rcur»ro‘):7/9,6 g. mol‘1
Ali
0E : Elsi/57%“)
: (A315 ~
haw féficlv‘e I075": I.
enz’fij Vim T’s
Chemistry 91164, 2017
\“ 74‘; tCQWO W)” PWJPL<
, 2 0.4m m’whit
FLO: will PM“? law"
QUESTION TWO ASSESSOR'SUSE ONLY
(a) (1') Draw the Lewis structure (electron dot diagram) for the following molecules, and nametheir shapes.
Approximate. <bond anglearound thecentral atom
,cL,,/\a/u,/,,,&# .3 of,
(Eaton; 7 {22/4 an ca (e 709,‘i’ QM,¢MM7[~ mfevhvrvs N V fla 7/100 ' /€7/m'.,, 7)),99/4’Qwas in / 52, t T/L’fi'/H"_flx‘ar7, ‘ 044C fi/e, C7. , /
__.__L
-5‘ flit/tr
Chemistry 91164, 2017
6
ASSESSOR'SUSE ONLY
(b) Three-dimensional diagrams for two molecules are shown below.
Molecule
(i) In the boxes above. identify the polarity of each molecule. by miting either polar ornon-polar.
(ii) Justify your choices.CCILHz eases/5’ atzcflcl Ems aAflzlLL Emis\81% lo 74; elecfloncéa-KM‘J/ (“load befiw‘ fwl‘chls, Adipurlgwe’l'flfoimafl. Willa ll1e Cliclfléwl, le gel/raid nrflew ol'fl‘vlr '5‘% Cl / flash» fie yam} WA»: ml ,5 m C. W171 fireCLH 19ml}, m Fake/Lg “TM claw ,3 M C/ WM hefar“! Wm M I; m :4. Due lo “#2 mammal?{Imlxre ayl The; mam/JV Di‘oklwpfimen‘a’“ "5 f0!“ étflc"“"il\m afar/a5 macaw/emu: # Is A» \'C‘Clg Cwes’é 5% l; C-C/ Re A? hm G/c’i/rw‘yrc’Jj}a raw or will, also; rm;
71/) #1;an} Warm 34/ at m disc/e ,s m cut/Mll: Pwr/Cll pas/wt end '5 llLL Ci ”' 1Howe“? (in: l0 l“ SdMe/frzai/ flat/ML yr (Ha, ’10Overall palm/1 I? gum/l 69am m C‘C/7)? .
eY/v’lfl C119 ,3 flan-flag}. I.
gym/16g! r Chemistry 91164, 2017
(C)
/,
LReaction N2H4(g) + 02(9) —» N2(g) + 2H20(g)
llydrazine. NzH4. is used as rocket fuel.
Use calculations to determine which of Reaction 1 or Reaction 2 releases more magiA
/’\i
/.Reaction 2." N2H4(Q) + 26(9) -* N2(9) + 4HF(9)
The structure of each chemical species is shown in the box below.
[::HH\ /N — N/ \
H Hhydrazine
H —O—Hwater
O=Ooxygen
F-Ffluorine
N—=Nnitrogen
H—Fhydrogen fluoride
Use the average bond enthalpies given in the tab e below.1
Bond Average Bond enthalpy Bond Average Bond enthalpy/kJ mol‘1 /kJ mol‘1
Show your working and include appropriate units in your answer.R: .— (:38 + tram) may) 4% + Mars) :is‘sn'
R2 .— Us? + trey”) r Lr—(ISq) )— Mus » MSW/7))gem/lean release; flue anew“ MIL!PxeaLl‘cm ave con/bx reg/Mes 337 K]: [4/ \
65g kf WMe 1’; SS ‘ .L71»
ASSESSOR'SUSE ONLY
l
Chemistry 91164, 2017
QUESTION THREE
(a) (‘omplete the table belou by statintU the type of solid. the type of particle. and the t} pe ofbonding (attractiVe forces) between the particles in each solid. 4' ""T
Type of solid Type of particle Attractive forcesbetween particles—_\ [
Solid
—|1—Al(s) /
(aluminium) I {l’le
MgCl2(s)(magnesium chloride)
S8(8) ’y'(sulfur)
A|(s)
Justify" your choice. referring to the attractive forces between the particles ol‘ALL threesubstances.
7m m M: t at“ arm 3 cl t; ,~ t r ‘ Ae WM (:0 5 I I 6 WA“ fle fife/1]A 'Qrc a.) fie” 7&7/9/g" - » ’ '-
‘
l; a #75 fl fl’hqlé up [IO/V) phrccl /C”j/AL/€ Nw/e,’ («J‘
tale mow—Y eta/m, 1),; Wed 3).”; meg/K 710 Lac/im atom» tam». neg/ea 177m: 57/, moo/)4S; .5 Cf mo/eeelm sags/ante Me VF Ag), Ave/gala. 57am [Waite/alr-Cm; loam [at] Weak ‘,;ql<~melgvlgv~ @153 Cal u/Li/r'm.
M‘élgi’ I flail Mucl't 9nd: 1.} / gremrwf (lo Zygk /\r fl( flu/xi} MIL “feral/7’
e“ if flag a [fly mc 04] Fun , W 7 w .L .7
i,5 an My»): c¢.~v/vv/’2U‘_Ml~ mwfe -72) ham 10‘s-wae prone “agile/Ll" Jeri/Le Lem/ill eralcdns/Jcam or camera not.“ at)“, (“Mazda/£14
Eng-33 ,2 fez/w“) 7Z0 Lat 71}7fl q A malfi')] far") A;
l. M/‘) “)4 L w it Vt/k/ brim-J
Chemistry 91164, 2017
‘ASSESSOR‘SUSE ONLY
ASSESSOR'SUSE ONLY
Question Threecontinues on thefollowing page.
Chemistry 91164. 2017
(Cl
10
CW.”Circle the substance which is malleable.
MgCl2(s) 88<s>Justify your choice by referring to the structure and bonding ofyour chosen substance.
You may include a diagram or diagrams in your answer.
mfilull belt as me Me up #0.» all-was 771,3
Cay/ABA (pvt p‘rer/l Parke nee/e; OWQ flJechrm fifti—Maa
elwlwpr 2e nude; M suWNJQ/l éj axe; (9+ flue
flié qMOv—é fie
L be 40,0-Jr'»ecl\ow/. ,‘s‘ V61 ed;
hie Shape»; Lead/w rail-i 77m. $7.; l
Bean»: ,1 a Mural/«Judd CW Ara/J;
fl‘f raids ink; sH/ cr/aps 3/2547
emellj m3 Vflmh are «cw-1Q flo/l Arch/C
SA 0/765
r3 (Lu/M flag/leolfl/fi, "flew/rug Lye/Lew Z mom]
§/xc‘/< lyre/ice
, _
C/e
\
3
:]Spacefor diagram
Chemistry 91164, 2017
'Assesson'si use ONLY
%
rm 9r 41% 71W WM (Melrt7\LD‘ mat/e PMrlvleg i
/ .
' "\p
11
Extra paper if required.Write the question number(s) if applic/able.
ASSESSOR'SUSE ONLY
QUESTIONNUMBER
Chemistry 91164, 2017
91164
QUESTION 1NUMBER “
12
Extra paper if required.Write the question number(s) if applicable.
Chemistry 91164, 2017
ASSESSOR‘SUSE ONLY
Subject: Chemistry Standard: 91164 Total score: 15
Q Grade score Annotation
1 M5
This candidate received a grade score of M5 as the response linked reaction processes to reaction progress, the attractions of water and NaCl, although without an accurate diagram, and correctly analysed the energy output of thermochemical calculations.
2 M5 This candidate received a grade score of M5 as the response linked electronegativity to bond polarity and bond enthalpies to one correct enthalpy change, although the unit was incorrect.
3 M5 This candidate received a grade score of M5 as the response linked two of the three attractive forces to the energy requirements of melting while also linking the malleability of aluminium to the non-directional nature of metallic bonding.