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ChemistryPaper 2

2 hours & 30 Minutes

Name________________________________ Grade__________________

READ THE FOLLOWING DIRECTIONS CAREFULLY

1. This paper consists of two 2! sections " and #. "nswer "$$ %uestions in each section.

2. ou must use this paper when respondin' to the structured %uestions. (or each %uestion)

write your answer in the space pro*ided and return the paper at the end of the

e+amination. (o,der ,ea*es wi,, -e pro*ided to answer the essay %uestions in section #

3. here appropriate) "$$ /NG M4T #5 46/N on this paper.

7. The use of non8pro'ramma-,e ca,cu,ators is a,,owed.

SECTION A 40 Marks

1. a! " student conducts an e+periment to compare the effect of temperature on the

so,u-i,ity of two sa,ts) and T. The data co,,ected are represented in ta-,e 1.

T"#$5 19 4/$#$T54 /( "N: T "T ;"/4 T5MP5"T54

Temperature oC! 4o,u-i,ity ' per 100' water!

T

10 2

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(4)

a. 4tate two uses of isotopes.

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-. ",thou'h there are more than one thousand isotopes) on,y a-out one hundred and

nine e,ements e+ist. Gi*e /N5 reason for this o-ser*ation.

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c. Natura,,y occurrin' si,*er is a mi+ture of two isotopes) 7>"' and 7>"'. 6owe*er)

its re,ati*e atomic mass is 10?. n contrast) a,thou'h natura,,y occurrin' car-on isa mi+ture of two isotopes) AC and AC) its re,ati*e atomic mass is 12. 5+p,ain how

this is possi-,e.

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T"#a$ 10 marks

3. 4tudents were asBed a num-er of %uestions -ased on the information 'i*en in ta-,e 2

TA%LE !& 'RO'ERTIES OF SOME METALS

M#a$s A#"mi N*m+r E$#r",i

Arra,-m,#

Ra#ii#. /i#

Wa#r

" _ 2) ?) 1 eacts *i'orous,y

with co,d water

# 20 _ eacts s,ow,y withwater at room

temperature

C 13 2) ?) 3 _

The fo,,owin' statements were taBen from one of the students note-ooBs. These

statements are NC/5CT. ou shou,d state why the statement is incorrect and 'i*e the

correct statement where re%uired.

i! NC/5CT 4T"T5M5NT9The atomic num-er of meta, " is 1 since it has one e,ectron in its outer she,,.

a! 5+p,ain why statement is incorrect9

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-! Correct statement9

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(4 marks)

ii! NC/5CT 4T"T5M5NT9

Meta, C forms ions of the type C

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S#i", % (31 Marks)

A,s/r a$$ *s#i",s

1. The properties of so,id su-stances depend upon

The properties of the partic,es they contain

The arran'ement of the partic,es The -ondin' -etween these partic,es

:ependin' upon their structure and properties) so,ids may -e c,assified as ha*in' 'iant

ionic) 'iant meta,,ic) 'iant co*a,ent or mo,ecu,ar ,attice structures

a! :raw the ,attice structure for 5ach of the fo,,owin'9

i5 :iamond

ii5 4odium Ch,oride 2 marks

-. :iscuss how 5"C6 of the fo,,owin' properties is re,ated to the ,attice

structure of diamond9i5 Me,tin' Point

ii5 Conduction of e,ectricity 4 marks

c. 4u''est possi-,e e+p,anations for 5"C6 of the fo,,owin' sets of o-ser*ations9

i5 Graphite is a non8meta,) yet it conducts e,ectricity. nc,ude a structure

of the 'raphite ,attice in your answer. 2 marks

ii5 hy ,i%uid ice is a-,e to f,oat in water 1 mark

iii5 hy is diamond is hardest natura, su-stance Bnown to man

! marks

d! #ased on your Bnow,ed'e of so,id air fresheners) wou,d you c,assify them asha*in' 'iant ionic) 'iant co*a,ent or mo,ecu,ar ,attice@ 5+p,ain your answer.

marks

T"#a$ !0 Marks

2. 4o,id) 'aseous and ,i%uid su-stances com-ine in *arious ways to form mi+tures. Theproperties of mi+tures depend on those of the su-stances that maBe them up. Theseproperties a,so ser*e as a means -y which mi+tures may -e c,assified and a -asis on

which they may -e separated.

a5 4uspensions) so,utions and co,,oids are e+amp,es of mi+tures. :istin'uish amon'

so,utions) suspensions and co,,oids (4 marks)

+5 " student carried out an e+periment to compare the so,u-i,ities of three sa,ts)

hydrated copper ! su,phate) potassium nitrate and sodium ch,oride at different

temperatures. Ta-,e 1 shows the data co,,ected durin' the e+periment.

T"#$5 19 C/MP"4/N /( 4/$#$T54 /( T655 4"$T4Temperature E oC Mass '! crysta,s disso,*ed in 100 cm3of water

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6ydrated Copper

! 4u,phate

Potassium Nitrate 4odium Ch,oride

10

2070

A0?0

1>

212=

700

3.33?.7

5 sin' the data in ta-,e 1) descri-e the effect of temperature on the so,u-i,ities of

hydrated copper ! su,phate) potassium nitrate and sodium ch,oride.

( marks)

65 /n the 'raph sheet pro*ided) p,ot the data for potassium nitrate

(2 marks)

5 (rom your 'raph9

i5 Predict how much potassium nitrate wi,, disso,*e at =0o

C.(! marks)

ii5 :etermine how much potassium nitrate wi,, -e precipitated if the so,utionis coo,ed from A0 oC to 10 oC. (! marks)

(T"#a$ 13 Marks)

3. Chan'e the fo,,owin' word e%uations into chemica, e%uations 'i*in' the state sym-o,s

and -a,ancin' them.

1. $ead ! nitrite F Tin man'anate $ead man'anate F Tin nitrite

2. $ead ! phosphate F inc chromate $ead chromate F inc phosphate

3. 4i,*er nitrate F copper ch,oride 4i,*er ch,oride F copper nitrate

7. #arium nitrate F 4u,phuric acid #arium su,phate F Nitric acid

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. Cu F 6C,

?. Na/6 F Cu4/7

=. M' F /2

10. "'N/3 F 2Cr/7

11. Cu F Na24/7

12. Ca/6!2 F 6C,

13. F P-N/3!2

17. #aC,2 F N67!2C/3

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