90944 909440 SUPERVISOR’S1 USE ONLY
Level 1 Science, 2017 90944 Demonstrate understanding of aspects of acids and bases
9.30 a.m. Wednesday 15 November 2017 Credits: Four
Achievement Achievement with Merit Achievement with Excellence Demonstrate understanding of aspects Demonstrate in-depth understanding of Demonstrate comprehensive of acids and bases. aspects of acids and bases. understanding of aspects of acids and bases.
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.
Pull out Resource Booklet 90944R from the centre of this booklet.
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 –8 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.
Excellence
TOTAL 22
ASSESSOR’S USE ONLY © 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 QualificationsAuthority. 2
QUESTION ONE USE ONLY
A sample of powdered sodium hydrogen carbonate (NaHCO3) was added to sulfuric acid (HrSOa) in a flask. and flzzing was observed. Two experiments were carried out with the acid at different temperatures, using the same amount of powdered sodium hydrogen carbonate and the same concentration and volume of sulfuric acid:
Experiment Temperature of acid, oC
1 30
2 55
(a) What caused the fizzing? ihr rtt (G,S 0- A* ca{-h:afi &" zxi d.t *N-hfnll*=NeLCQ-+ -ancl lle& {< dct.
(b) Why was the fizzrng fastest immediately after the sodium hydrogen carbonate had been added? Your answer should refer to particle collisions. As- rhr ! qY [c-s LLn.cl-HzS0-** p-c,r!.r.c-l-t-s*r:,0-itrds -uith,latughznsryyaad tht mutel-ariLnla:ttoh,a"J9-4c1!8J1--t n Sultq!fuAgkv a44 cayksn-d,Sxi&-{!1-4-f!24!ng is the vcaNe of tA!
carJ 0 n d t eX I d! rytrufu_a_e n the re a rc the no,rl Jt_j_€_f0Stf_Stjffi/i;o,ii"'-,, /g*wt* i/raeta4bl,**..r -pq4!e !!l auliqlle t'Oy re !u: i i,-ns- twusdtatilyafltv rht ttdiifa,Mr , . t-lLt* n$*Wqn Vhe r< forc tlte moJt rarbon rlio, i1. hol +htrc&rc is ttv 1_ volume of gas produced time Science 9A944,2017 3 Ret-er to the graph otr the previous page to answer the following question: What is the effect of itrcreasing temperature on the rate of reaction? Your answer should ref-er to parlicle collisions and explain w'hy both lines flnish at the same point. infitaS t ng thr- icm pru f-!t re inci:e.Arc_-{- t'_Ae arnoa nt_ q -tu n€-tr:e- €h€_rgy_ fh€_ partlc-(e-{*.1rur& fl:l-s Me-a&{ rAegt {€ f_qr-:"ter_ am(*aye _ryl?_f,g_ "no- Nilh fhe !'qrrec+ oiri"('n4 fo-te itrele w-{th -a-rh trJ€4ctuat-?a rf(e ler:'e-{ahy-.gt-t"y!-n -t-ister.ta - ta r-ut rea At iQrtT*Jhrt i s uvhy-tht, t/o- I ll !fr-:-e- e f- gat. P r QCored a tSf'c Ls highu than:ha't pf- lAl-c- at--tlf -0"egtonnE ai tht re_4_4?-?t:_ Sofh-lintS {in-ish .at-th!_.to,_ut_e_ pa_in* boe qaJe_ a f f_€t: &a_st_ zf_ffie f-ta e i a tlL p,a r-|Jc-EL L2-aL€-ielt r fu-d--and{- - {t a r trd a / r e alyn fatte a{e-ja!d-*a. -d:e{,u itJl-and-ta q J4tgE4:FQcer-!-t-4-en tu.?ke-Er-au-A,te fo-r- th*c-,p-61-(rte-kL ts fihd eacaa$€t-oqd rolrrve rut4_.9_b?qZA tn( rq,q r0 iort\ 1r.zec lioh s anl r €/€Qsc 6-0z, L,AtfbA/,$4 CYe/1 i i io{,ie \rtArc, n40/t /1{/ 'i"il rei'. 2ni. 'rh€ r{in,oi'&./utz ,ttor-ria/ /)'ft(/q n*rc ia"weiezl, t@cdning rhz"ti lhc Ff,1r/ic'/e.t 4/? ttct/i4or,)q'* .(-?!t ,{t "t,, !it€1. -i/?fe rh€ J'rzit't-t'it(t(l'o;e itci|.t11(t.fri/l_i.^gl ,rciry'7'pt{t, (d) Write a word equation AND a balanced sl,mboi equation for the reactioir between sodium hydrogen carbonate Q.JaHCO3) and sulfuric acid (H.SOa). Word equation: S,rof ium hVd toge^ carbonale + Sulf Jri' c qcid Sutfa*e rwate v r cerhoo -?Sodi,,.rnn diCxid( Balanced symbol equation: N"4HCC3tH25C1 - No*SC1 ,ZHrC QC), Science 9A944,2017 4 euEsrroN rwo l^i:::.; Sodium and potassium are both highly reactive metals that react with oxygen gas. However, sodium I potassium and do not react with each other. I I (a) Why do sodium and potassium each react with oxygen, but not with each other? I "'}fl* i :,i:l{kru;::ffi;::Til::H: :*Tr::iil:H.,- I the periodic table I ' explain how an ionic bond forms when sodium or potassium reacts with oxygen. I flir icnic bcr-tcl ('ornng v,shen apcsrfflvel| cha(qlcd tCn (eac I fs vn t th a ne gcll i v e ig e h-,(tr rge<' i cti.," [J:r?Jy,,r,,o.l Chctrqecl rait iS {o'(med u*)hen amatc.u.tl^l,e&{E^lrnp8i-J /oSe Su''"Arrofl I e iect ror-,stpaonetf if"'J?E'7"uue +he a-v€{att cn,.-,, qc be.t.c,n-J1 ertclrons p.,si'ti ve as th e v'€ ave an exce sscf p I ot.,.s'i?ffiaru I neqativelrl c'bczrgeci to)\ is {-ori.nec} wi.^e n an cr/c:no I n as 5 '7 elecl r cr-t,( in it'.s yycllctn( e .\heil anci r t I e lecf(Oi1s,tnckri:J /.1.e ,v^lrOtAG charrJA i1(?atlve larns I Eofh ScCtdtr\ etnd pc.rass tum c,ir,€ in gr.oup Z on il* I I t, t'c c'l c t,t the Pe [X.t,t!;,t'i,i'" ;I;":;:,:,,,m,r701{,\,rr'n*?,.ri,ill, '"1 valance .s/,s lt.^11t o,'"lc( tc oicc,,-r',e ,.srctZla, K a,"c,,{ il"*' neec/ fu;l ro,,e rh i s? o,r, t)LTr'*',iii"![,7i'";i')'rl"::,P,"0'5,ja''ir',:;y'i ^o,,,rl ant ir^ore p(o-t7t4 thah elecrrontKhcrs tq pancl t0E ancl i {Va haS lt f anol tAE,rherefOi,e th(? rfiatc€ po,;itiv,ely charfu iOrl.S,0tyqen I ,s tt1 Jtcap r6 cnt rhe Fct, o{.lrrlr,;r,r,fl"ll[!;!r;f l:{* I ikrr/ if hc,s C e lrCti,anS ,:n ,ts' /ct/orttc Sietl;ti)lriff7; I hftcm( ..5.ic,tbrc, it t'{1ti/,sr Ta i n i e idc'+tcitJ;c f'arlyt a f'tilt t.ru} ,;hell,.et((f,on ayroittq4,6o€t-11 Z,E. t.t calfi clc this D"t fc;.rnrnQ tral -'r io;..io t:c,n.C w;rl1 Mi ffif Na olnl l('trc-rh"lr:'rr^rrlntuA tl'te/;t'rFt'av;',ie-'q, JtJln'lj'i"i'fir,.'r^ra?n cJcttn .tc rv"'v-"v!^,i^uo',Inrirnorh(t'c'('ore I : au t1i'f lrd,^,"-,tr, ru liil ir'J D\LJ,q(h cJ"i,ns o,"7|n"u',.ri ,,, /rri,"", negh*iv,t tt1 churrycl (^C)'):!!, "io'.iiri/e I ;s ittruc leol ,o rq I (.kurr7tci..i0;tr(Kr'1 Ata')'rafo/n^^rlt' un ,o,1 i( noi,tc/. l<" 4iUr,r l ,.trcn'I'11flr,7(t €utth urh (b) Three unlabelled colourless solutions are know-n to be: . nitric acid (HNO,) . sodium chloride (NaCl) . sodium hydrogen carbonate lNaHCO3). How could each of these unlabelled solutions be identified using only potassium cartronate (K2CO,) solution, and red litmus paper? In your answer you should: . colltplete the table . explain how'the observ'ations allou 1-ou to identifi, each solution . include balanced symbol equarion(s) for any reactions. Unlabelled solution Obsen'ation (if an1.) u,ith Observation (if any) with red litmus paper potassium carbonate (qCO3) litmus paper trrq?rrcd Buboes produ(€cl a/\d Nitric acid (HNO,) Ca|ho,t ciiol"ic"{Z i5 feieet S ed No Ol2sefva+for1 " Sodium chloride No ehservc).riat^ - L ff m tls Pot Per s+a99 QtlaCl) re d. NO abSet/\l at"rlOa Sodiurn hl,drogen i;tt'Ytu,t PAPer i-t4rnI btqt carbonate Q{aHCO3) IrJ e co-n irle n:t i{-q-:the ru;n i r a c i d*tcnotirfr!{?i{*fr,t.{"fiZi tf,i$ rra udi egtinq lhat tt- iL nai. basi L-uul a crdic -and-b u bbles at e-t( produced taJhen .Lht pl.t-ass i arn ca!_bpna-te _aJaradd_€cl, ind k atinq the_ {-€_Gq,tr t) f cq v t00 n di 0 r,ar':iliu'ii r#fr#.t'ffi#, a y bc n a ; ts a6t6/ed lo an -a ei d'-itLs -cctn i de.N+Tt he--sadi uyvt -agdtay n ea-( byfiat_c_s:w, ue-k-no-ur-if- iS- a.--baso aLd ii t-u{ngd.rJqe yi,d l{ifr)WpaperlJue, indi c atioL rn^t *W sa iutrcnis-busic " Thgrc -iaas- no-0bret'v--att"gh -r1)hEt4 -kz-c1* u-ac-added-a,tb-o,f_h at:€_ bas-95 -a-nrtr- da_n:t rtac_t,-dp_diuru Chtedels i's_a_,ratt tA,tr_c{o_r-e_r} 19!,ghgryfr tbe Utctr.tr (t/ rtne tir,r,ytus paper ad il it n-ciabarq Th?re f-Oi€u ChAnQe occet/r.eo/ ' nd /., _ Balanced sy'mbol equation(s): tuOq t KzC)t '-;ZKflJCa t HzO r CCz Science 90944,2017 L 6 QUESTION THREE (a) (i) Explain why silver oxide, AgrO, has a 2:1 ratio of ions. In your answer you should: . relate the ratio of ions to the number of electrons lost or gained by each atom when forming ions . explain how the ratio of the ions in the compound is related to the charge on the ions. Ihr,sjrue r_ i rff i r d flLtt Luw{ .s he! !, ry-q.Kii& t t-nsgglu4I oq:94!!:*): ih-ls - fA€L\rt1S- fh ct't it iC it; are- rue-d*p r- e- rei: 0 ?- i o-n ea f,*h a aides-o-ae-e I ec :t t'en - y * hr - p$) .the *o jara l_JW O_ +'c; r Ot'|tq,ert'ty'-* i?h-- f0'-v-* Tair't. Ne need 2 fdr ih?_ LqnS_:_q_?' 1' Le__tLdg 2 -e!p_cj_t{9y6-ta_ bs|a!_aE out Ca_Ul!,_ltuL hq,, d1't. '"4, ali/it rdth 4p*ave{q1/,cdarge sfnc€---- - tronic Coff pOwnc,{t cth€ he ilfi/A /" (ii) Silver oxide is a base and will react with hydrochloric acid. Write a word equation AND a balanced symbol equation for the reaction betw-een silver oxide and hydrochloric acid. Word equation: Sitvev oxic)e r ilqo/ rolhtorie acial --? J i tver chloriole r w ate t Balanced symbol equation: AE, O *Z?IC t --) Lngcl t HzC tol r-14 I Science 90944,2017 7 (b) A solution of sodium }ydroxide q"o!) is slowly stirred into a beaker of hydrochroric (HCl) with acid ASSESSOR'S universal indicator added. The HCI USE ONLY and universal indicator soluiion starts out red. HCI + uniysl5sl indicator Explain the changes in the colour of the universal indicator as the sodium hydroxide is slowly solution added until no further colour changes occur. In your answer, you should: . relate the changes in the colour of the universal indicator to the approximate solution pH of the . link the pH to the relative concentrations of i. drogen ions and hydroxide solution ions in . explain the neutralisation reaction occurring. Hgi-Li a yty+.stwM$ et-o-iafii1j!tur!:r:!attC_wtt_h a pJt_o_f_ J:Z_q$_t/__-_ ril e q s-eL u A%^ x,ssci Hgdr e#eilu a itns r n r n -wa - -00- &.t-a e r -i*tlt. w-at-€_ t ; frs--w-dturn Ly rl t:ori ('t e (Na 0 il)rs-adde-druc- ayil:onde t e H) it ns h,al qnc_e- wth anrl a-at ;:Arme-pf-th€ j -\.!znc€J €ret;$_t__l!- OnSr Lr)ak1n! ir_ A_weArf_et^ I DaJ L- i/llith a 7H af -3*a a*ataaTeg -c-ctout t-r) u-t tt4u!rcbqlryd14ors4. A;--ma-'{& l\l-a-Q-H-t's- as{c/e-dt-ffia-{-€-0tiet{--eu-c r-e-le-qre-d/-rd tr) t:enceiL'qrlC€/ cut'6:4_t srtll tltithtt(esg HriH) fna{f Hr L.a-nd anol ir bs_e.D-ru{d_d_wtaJ-{ aqld p*A- { _O:A!A?_iiiw cQia-4 t,, ! I bl_ _a ug.s ?9_14 Laa t {q1_ uhea _tt_fit1,_a1 g rc94 vttA_ayi-t pA-a_f Z-,m N-( u t { E ! tt: E_t-i"_a_ A q,r n 0ccdo, ttr€d andn cl r-l-t{i., b-e t' Ur*e r_a_e{C a Hr and a-H- L 0nr-r^bt:ei-€ach-oLhrr-o-47, fu-as ma_re_ ak c_Hts added, - dcltd, n0_,"g0{€,,?!, qr/{ 't_ a#ot{;;*3n*'o;[' s;i'ii"'q 9;4 L^;i' 1',t-r^ ngS,s.,(tl.=_0_-C,c ls ir i$rs aatrcqatt t\ore ;ii',t' h';,{€igti;{g;# r'ii'i''ff ';;?,"; ;0 fi- it) dlt.,,i,tt.t rr^.. ,^ n t^ t',3 ili';i!,nr 1,,':;ff;riritli/f:! q€n ir":, h ._ n: Subject: Science Standard: 90944 Total score: 22 Grade Q Annotation score This provides evidence towards merit as the candidate explains the effect of higher concentration of reactant particles early in a reaction and further merit, the effect of higher temperature on collision rate. They have not explained why 1 M6 reaction rate decreases for excellence or that increased temperature affects collision force/energy or that both reactions have the same reactant mass and product (gas) volume for excellence. The equation is correct for excellence. A comprehensive answer explaining both parts of the question. Excellence is shown in why Na and K can react with O but not each other, including ion and 2 E8 ionic compound formation and group relevance. Excellence is also shown in how the 3 solutions can be identified and the equation is correct for excellence. A comprehensive answer covering all excellence points. The candidate explains that an ionic compound requires both electron transfer and a neutral charge for excellence and correctly balances the equation for excellence. Also 3 E8 for excellence, the candidate outlines the changing pH, colours and relative hydrogen and hydroxide ion concentrations. The explanation of neutralisation is missing the production of water/salt/neutral substances but shows a high level of understanding overall for this question.