da

y Ju

ne 2

0XX

– M

orni

ng/A

ftern

oon

A Le

vel C

hem

istr

y A

H43

2/01

Pe

riodi

c ta

ble,

ele

men

ts a

nd p

hysi

cal c

hem

istr

y SA

MPL

E M

ARK

SC

HEM

E

D

urat

ion:

2 h

ours

15

min

utes

M

AXIM

UM

MAR

K

100

Th

is d

ocum

ent c

onsi

sts

of 2

4 pa

ges

Specim

en

PMT

H43

2/01

M

ark

Sche

me

Ju

ne 2

0XX

2

MAR

KIN

G IN

STR

UC

TIO

NS

PR

EPAR

ATIO

N F

OR

MAR

KIN

G

SCO

RIS

1.

Mak

e su

re th

at y

ou h

ave

acce

ssed

and

com

plet

ed th

e re

leva

nt tr

aini

ng p

acka

ges

for o

n-sc

reen

mar

king

: sco

ris a

sses

sor O

nlin

e Tr

aini

ng;

OC

R E

ssen

tial G

uide

to M

arki

ng.

2.

Mak

e su

re th

at y

ou h

ave

read

and

und

erst

ood

the

mar

k sc

hem

e an

d th

e qu

estio

n pa

per f

or th

is u

nit.

Thes

e ar

e po

sted

on

the

RM

Cam

brid

ge

Asse

ssm

ent S

uppo

rt Po

rtal h

ttp://

ww

w.rm

.com

/sup

port/

ca

3.

Log-

in to

sco

ris a

nd m

ark

the

requ

ired

num

ber o

f pra

ctic

e re

spon

ses

(“sc

ripts

”) an

d th

e re

quire

d nu

mbe

r of s

tand

ardi

satio

n re

spon

ses.

YOU

MU

ST M

ARK

10 P

RAC

TIC

E AN

D 1

0 ST

AND

ARD

ISAT

ION

RES

PON

SES

BEFO

RE

YOU

CAN

BE

APPR

OVE

D T

O M

ARK

LIVE

SC

RIP

TS.

MAR

KIN

G

1.

Mar

k st

rictly

to th

e m

ark

sche

me.

2.

Mar

ks a

war

ded

mus

t rel

ate

dire

ctly

to th

e m

arki

ng c

riter

ia.

3.

The

sche

dule

of d

ates

is v

ery

impo

rtant

. It i

s es

sent

ial t

hat y

ou m

eet t

he s

coris

50%

and

100

% (t

radi

tiona

l 50%

Bat

ch 1

and

100

% B

atch

2)

dead

lines

. If y

ou e

xper

ienc

e pr

oble

ms,

you

mus

t con

tact

you

r Tea

m L

eade

r (S

uper

viso

r) w

ithou

t del

ay.

4.

If yo

u ar

e in

any

dou

bt a

bout

app

lyin

g th

e m

ark

sche

me,

con

sult

your

Tea

m L

eade

r by

tele

phon

e, e

mai

l or v

ia th

e sc

oris

mes

sagi

ng s

yste

m.

Specim

en

PMT

H43

2/01

M

ark

Sche

me

Ju

ne 2

0XX

3

5.

Wor

k cr

osse

d ou

t:

a.

whe

re a

can

dida

te c

ross

es o

ut a

n an

swer

and

pro

vide

s an

alte

rnat

ive

resp

onse

, the

cro

ssed

out

resp

onse

is n

ot m

arke

d an

d ga

ins

no

mar

ks

b.

if a

cand

idat

e cr

osse

s ou

t an

answ

er to

a w

hole

que

stio

n an

d m

akes

no

seco

nd a

ttem

pt, a

nd if

the

incl

usio

n of

the

answ

er d

oes

not

caus

e a

rubr

ic in

fring

emen

t, th

e as

sess

or s

houl

d at

tem

pt to

mar

k th

e cr

osse

d ou

t ans

wer

and

aw

ard

mar

ks a

ppro

pria

tely

.

6.

Alw

ays

chec

k th

e pa

ges

(and

add

ition

al o

bjec

ts if

pre

sent

) at t

he e

nd o

f the

resp

onse

in c

ase

any

answ

ers

have

bee

n co

ntin

ued

ther

e. If

the

cand

idat

e ha

s co

ntin

ued

an a

nsw

er th

ere

then

add

a ti

ck to

con

firm

that

the

wor

k ha

s be

en s

een.

7.

Ther

e is

a N

R (N

o R

espo

nse)

opt

ion.

Aw

ard

NR

(No

Res

pons

e)

- if

ther

e is

not

hing

writ

ten

at a

ll in

the

answ

er s

pace

- O

R if

ther

e is

a c

omm

ent w

hich

doe

s no

t in

any

way

rela

te to

the

ques

tion

(e.g

. ‘ca

n’t d

o’, ‘

don’

t kno

w’)

- O

R if

ther

e is

a m

ark

(e.g

. a d

ash,

a q

uest

ion

mar

k) w

hich

isn’

t an

atte

mpt

at t

he q

uest

ion.

Not

e: A

war

d 0

mar

ks –

for a

n at

tem

pt th

at e

arns

no

cred

it (in

clud

ing

copy

ing

out t

he q

uest

ion)

. 8.

Th

e sc

oris

com

men

ts b

ox is

use

d by

you

r Tea

m L

eade

r to

expl

ain

the

mar

king

of t

he p

ract

ice

resp

onse

s. P

leas

e re

fer t

o th

ese

com

men

ts

whe

n ch

ecki

ng y

our p

ract

ice

resp

onse

s. D

o no

t use

the

com

men

ts b

ox fo

r any

oth

er re

ason

.

If yo

u ha

ve a

ny q

uest

ions

or c

omm

ents

for y

our T

eam

Lea

der,

use

the

phon

e, th

e sc

oris

mes

sagi

ng s

yste

m, o

r em

ail.

9.

As

sist

ant E

xam

iner

s w

ill se

nd a

brie

f rep

ort o

n th

e pe

rform

ance

of c

andi

date

s to

thei

r Tea

m L

eade

r (Su

perv

isor

) via

em

ail b

y th

e en

d of

the

mar

king

per

iod.

The

repo

rt sh

ould

con

tain

not

es o

n pa

rticu

lar s

treng

ths

disp

laye

d as

wel

l as

com

mon

erro

rs o

r wea

knes

ses.

Con

stru

ctiv

e cr

itici

sm o

f the

que

stio

n pa

per/m

ark

sche

me

is a

lso

appr

ecia

ted.

Specim

en

PMT

H43

2/01

M

ark

Sche

me

Ju

ne 2

0XX

4

10.

For a

nsw

ers

mar

ked

by le

vels

of r

espo

nse:

R

ead

thro

ugh

the

who

le a

nsw

er fr

om s

tart

to fi

nish

, con

cent

ratin

g on

feat

ures

that

mak

e it

a st

rong

er o

r wea

ker a

nsw

er u

sing

the

indi

cativ

e sc

ient

ific

cont

ent a

s gu

idan

ce. T

he in

dica

tive

scie

ntifi

c co

nten

t ind

icat

es th

e ex

pect

ed p

aram

eter

s fo

r can

dida

tes’

ans

wer

s, b

ut b

e pr

epar

ed to

re

cogn

ise

and

cred

it un

expe

cted

app

roac

hes

whe

re th

ey s

how

rele

vanc

e.

Usi

ng a

‘bes

t-fit’

app

roac

h ba

sed

on th

e sc

ienc

e co

nten

t of t

he a

nsw

er, f

irst d

ecid

e w

hich

set

of l

evel

des

crip

tors

, Lev

el 1

, Lev

el 2

or L

evel

3,

best

des

crib

es th

e ov

eral

l qua

lity

of th

e an

swer

usi

ng th

e gu

idel

ines

des

crib

ed in

the

leve

l des

crip

tors

in th

e m

ark

sche

me.

O

nce

the

leve

l is

loca

ted,

aw

ard

the

high

er o

r low

er m

ark.

Th

e hi

gher

mar

k sh

ould

be

awar

ded

whe

re th

e le

vel d

escr

ipto

r has

bee

n ev

iden

ced

and

all a

spec

ts o

f the

com

mun

icat

ion

stat

emen

t (in

ita

lics)

hav

e be

en m

et.

The

low

er m

ark

shou

ld b

e aw

arde

d w

here

the

leve

l des

crip

tor h

as b

een

evid

ence

d bu

t asp

ects

of t

he c

omm

unic

atio

n st

atem

ent (

in it

alic

s)

are

mis

sing

. In

sum

mar

y:

• Th

e sc

ienc

e co

nten

t det

erm

ines

the

leve

l. •

The

com

mun

icat

ion

stat

emen

t det

erm

ines

the

mar

k w

ithin

a le

vel.

Leve

l of r

espo

nse

ques

tions

on

this

pap

er a

re 1

9(d)

and

22(

b).

Specim

en

PMT

H43

2/01

M

ark

Sche

me

Ju

ne 2

0XX

5

11.

Anno

tatio

ns

Anno

tatio

n M

eani

ng

DO

NO

T AL

LOW

An

swer

s w

hich

are

not

wor

thy

of c

redi

t

IGN

OR

E St

atem

ents

whi

ch a

re ir

rele

vant

ALLO

W

Answ

ers

that

can

be

acce

pted

( )

Wor

ds w

hich

are

not

ess

entia

l to

gain

cre

dit

__

Und

erlin

ed w

ords

mus

t be

pres

ent i

n an

swer

to s

core

a m

ark

ECF

Erro

r car

ried

forw

ard

AW

Alte

rnat

ive

wor

ding

OR

A

Or r

ever

se a

rgum

ent

Specim

en

PMT

H43

2/01

M

ark

Sche

me

June

20X

X

6

12.

Subj

ect-s

peci

fic M

arki

ng In

stru

ctio

ns

IN

TRO

DU

CTI

ON

Yo

ur fi

rst t

ask

as a

n Ex

amin

er is

to b

ecom

e th

orou

ghly

fam

iliar w

ith th

e m

ater

ial o

n w

hich

the

exam

inat

ion

depe

nds.

Thi

s m

ater

ial i

nclu

des:

•

the

spec

ifica

tion,

esp

ecia

lly th

e as

sess

men

t obj

ectiv

es

• th

e qu

estio

n pa

per

• th

e m

ark

sche

me.

Yo

u sh

ould

ens

ure

that

you

hav

e co

pies

of t

hese

mat

eria

ls.

You

shou

ld e

nsur

e al

so th

at y

ou a

re fa

milia

r with

the

adm

inis

trativ

e pr

oced

ures

rela

ted

to th

e m

arki

ng p

roce

ss. T

hese

are

set

out

in th

e O

CR

bo

okle

t Ins

truc

tions

for E

xam

iner

s. If

you

are

exa

min

ing

for t

he fi

rst t

ime,

ple

ase

read

car

eful

ly A

ppen

dix

5 In

trod

uctio

n to

Scr

ipt M

arki

ng:

Not

es fo

r New

Exa

min

ers.

Pl

ease

ask

for h

elp

or g

uida

nce

whe

neve

r you

nee

d it.

You

r firs

t poi

nt o

f con

tact

is y

our T

eam

Lea

der.

Specim

en

PMT

H43

2/01

M

ark

Sche

me

June

20X

X

7 SE

CTI

ON

A

Q

uest

ion

Answ

er

Mar

ks

Gui

danc

e

1 A

1

2 B

1

3 C

1

4 D

1

5 C

1

6 D

1

7 C

1

8 D

1

9 C

1

10

C

1

11

A 1

12

D

1

13

D

1

14

B 1

15

D

1

To

tal

15

Specim

en

PMT

H43

2/01

M

ark

Sche

me

June

20X

X

8

SEC

TIO

N B

Q

uest

ion

Answ

er

Mar

ks

Gui

danc

e 16

(a

)

2s2p

2 AL

LOW

hal

f hea

ded

arro

ws

(b

)

The

forw

ard

reac

tion

is e

xoth

erm

ic, s

o an

incr

ease

in

tem

pera

ture

favo

urs

the

back

war

d re

actio

n (o

wtte

)

ther

efor

e th

ere

will

be m

ore

N2 a

nd H

2 OR

less

NH

3 in

the

equi

libriu

m m

ixtu

re, A

ND

ther

efor

e th

e va

lue

of th

e eq

uilib

rium

con

stan

t will

decr

ease

(ow

tte)

2 AL

LOW

nam

es o

f com

poun

ds

ALLO

W re

acta

nts/

prod

uct i

nste

ad o

f co

mpo

unds

2nd

mar

k on

ly a

vaila

ble

if de

duce

d fro

m 1

st m

ark

ALLO

W E

CF

for 2

nd m

ark

(c)

FI

RST

CH

ECK

TH

E AN

SWER

ON

TH

E AN

SWER

LIN

E IF

ans

wer

= 2

.37 ×

10–6

kPa

–2 a

war

d 5

mar

ks

IF a

nsw

er =

2.3

7 ×

10–6

with

inco

rrec

t uni

ts a

war

d 4

mar

ks

At e

quilib

rium

, n(

H2)

= 0

.300

(mol

) AN

D

n(N

H3)

= 0

.100

(mol

)

p(N

2) =

×

500

= 2

50 k

Pa A

ND

p(H

2) =

×

500

= 1

87.5

kPa

AN

D

p(N

H3)

=

× 50

0 =

62.5

kPa

Kp

=

=

= 2.

37 ×

10–6

k

Pa–2

5 Fi

nal a

nsw

er m

ust b

e co

rrec

t and

hav

e th

e co

rrec

t uni

ts to

sco

re a

ll fiv

e m

arks

AL

LOW

cal

cula

tor v

alue

for K

p cor

rect

ly

roun

ded

to th

ree

or m

ore

sign

ifica

nt fi

gure

s.

If th

ere

is a

n al

tern

ativ

e an

swer

, che

ck to

see

if

ther

e is

any

EC

F cr

edit

poss

ible

usi

ng

wor

king

bel

ow

Cor

rect

val

ues

subs

titut

ed in

to c

orre

ct

expr

essi

on fo

r Kp g

ains

firs

t thr

ee m

arks

.

Specim

en

PMT

H43

2/01

M

ark

Sche

me

June

20X

X

9

Que

stio

n An

swer

M

arks

G

uida

nce

(d

)

FIR

ST C

HEC

K T

HE

ANSW

ER O

N T

HE

ANSW

ER L

INE

IF a

nsw

er =

258

0 (to

nnes

) aw

ard

3 m

arks

n(

NH

3) =

1

.96 ×

1010

OR

8.1

67 ×

108 (m

ol)

24

AND

n(

H2)

= 8

.167

× 1

08 × 3

= 1

.225

× 1

09 (mol

)

2

Mas

s of

H2 =

2.4

50 ×

109

= 24

50 (t

onne

s)

1 ×

106

Mas

s of

H2 f

or 9

5% y

ield

= 2

450 ×

100

= 25

80 (t

onne

s)

95

3 If

ther

e is

an

alte

rnat

ive

answ

er, c

heck

to s

ee

if th

ere

is a

ny E

CF

cred

it po

ssib

le u

sing

w

orki

ng b

elow

AL

LOW

2.5

8 ×

103 to

nnes

AW

10

0% y

ield

= 2

.063

× 1

010 d

m3

Amou

nt o

f NH

3 = 8

.596

× 1

08 mol

AN

D

Amou

nt o

f H2 =

1.2

89 ×

109 m

ol

M

ass

of H

2 = 2

580

(tonn

es)

AL

LOW

257

9 (to

nnes

) (ca

lcul

ator

ans

wer

ro

unde

d to

nea

rest

who

le n

umbe

r)

(e)

(i)

2NH

3 +

NaO

Cl →

N2H

4 +

NaCl

+ H

2O

1

(ii)

NN

H

HH

H

107o

Bo

nd a

ngle

107

°

2 D

iagr

am m

ust a

ttem

pt to

sho

w g

eom

etry

aro

und

the

nitro

gen

atom

to b

e py

ram

idal

AL

LOW

106

–108

°

Tota

l 15

Specim

en

PMT

H43

2/01

M

ark

Sche

me

June

20X

X

10

Que

stio

n An

swer

M

arks

G

uida

nce

17

(a)

(i)

FIR

ST C

HEC

K T

HE

ANSW

ER O

N T

HE

ANSW

ER L

INE

IF a

nsw

er =

0.1

63 d

m3 m

ol–1

s–1

OR

0.1

632

dm3 m

ol–1

s–1

awar

d 4

mar

ks

IF a

nsw

er =

0.1

63 O

R 0

.163

2 w

ith in

corr

ect u

nits

aw

ard

3 m

arks

O

rder

w.r.

t. ICl =

1 a

nd o

rder

w.r.

t H2 =

1

ra

te =

k[ICl][

H2]

k

= 2

.04 ×

10–2

=

0.1

63 O

R 0

.163

2

dm3 m

ol–1

s–1

0.25

0 ×

0.50

0

4 If

ther

e is

an

alte

rnat

ive

answ

er, c

heck

to s

ee

if th

ere

is a

ny E

CF

cred

it po

ssib

le u

sing

w

orki

ng b

elow

Bo

th o

rder

s =

1 m

ark

Cor

rect

rate

equ

atio

n or

rear

rang

ed fo

rm =

1

mar

k C

andi

date

s m

ay u

se e

xper

imen

tal d

ata

from

ex

perim

ents

2 o

r 3 to

cal

cula

te th

e ra

te c

onst

ant

DO

NO

T AL

LOW

0.1

6

(ii)

rate

= k

[ICl][

H2]

(from

(i))

= 0.

163 ×

3 ×

10–3

× 2

× 1

0–3 =

9.7

8 ×

10–7

(mol

dm

–3 s

–1)

1 AL

LOW

EC

F fro

m (i

) N

ote

use

of 0

.163

2 fro

m (i

) giv

es 9

.79(

2) ×

10–7

Specim

en

PMT

H43

2/01

M

ark

Sche

me

June

20X

X

11

Que

stio

n An

swer

M

arks

G

uida

nce

(b

)

C

orre

ct c

urve

for h

ighe

r tem

pera

ture

Activ

atio

n en

ergy

sho

wn

on d

iagr

am

AND

gr

aph

show

s th

at a

t hig

her t

empe

ratu

re (o

wtte

) m

ore

mol

ecul

es h

ave

ener

gy a

bove

act

ivat

ion

ener

gy

OR

mor

e m

olec

ules

hav

e en

ough

ene

rgy

to re

act

2 Bo

ltzm

ann

dist

ribut

ion

– m

ust s

tart

at o

rigin

and

m

ust n

ot e

nd u

p at

0 o

n y-

axis

i.e.

mus

t not

to

uch

x-ax

is a

t hig

h en

ergy

M

axim

um o

f cur

ve to

righ

t AN

D lo

wer

than

max

imum

of l

ower

tem

pera

ture

cu

rve

AND

abo

ve lo

wer

tem

p lin

e at

hig

her e

nerg

y as

sh

own

in d

iagr

am

link

to g

raph

requ

ired

for m

ark

To

tal

7

Specim

en

PMT

H43

2/01

M

ark

Sche

me

June

20X

X

12

Que

stio

n An

swer

M

arks

G

uida

nce

18

∆H c

alcu

latio

n fr

om e

xper

imen

t q

= 1

00 ×

4.1

8 ×

20.5

OR

856

9 J

OR

8.5

69 k

J

Amou

nt o

f but

an-1

-ol =

0.2

59 =

3.5

× 1

0–3 m

ol

74

∆H =

−24

48 k

J m

ol–1

∆S

cal

cula

tion

∆S

= S

prod

ucts –

Sre

acta

nts

∆S =

(4 ×

214

) + (5

× 7

0) –

[(22

8) +

(6 ×

205

)] O

R

∆S =

120

6 –

1458

∆S =

–25

2 J

K–1 m

ol–1

OR

−0.

252

kJ K

–1 m

ol–1

∆G c

alcu

latio

n

∆G =

∆H

− T

∆S

∆G =

–24

48 –

(298

× –

0.25

2)

∆G

= –

2373

(kJ

mol

–1)

7 AL

LOW

Cal

cula

tor v

alue

for ∆

H =

−2

448.

2857

14 c

orre

ctly

roun

ded

to th

ree

or

mor

e si

gnifi

cant

figu

res

Mar

k fo

r use

of c

orre

ct e

xpre

ssio

n w

ith ∆

S in

kJ

K−1

mol

−1

ALLO

W th

ree

or m

ore

sig

figs

for ∆

G

To

tal

7

Spe

cimen

PMT

H43

2/01

M

ark

Sche

me

June

20X

X

13

Que

stio

n An

swer

M

arks

G

uida

nce

19

(a)

M

g(s)

+ 2

HCl(a

q) →

MgCl 2(

aq) +

H2(

g)

Ef

ferv

esce

nce

AND

sol

id d

isso

lves

2 St

ate

sym

bols

are

requ

ired

ALLO

W s

olid

dis

appe

ars

(b

)

Latti

ce e

ntha

lpy

of M

gCl 2 is

mor

e ex

othe

rmic

than

CaCl 2

be

caus

e m

agne

sium

ion/

Mg2+

is s

mal

ler (

than

cal

cium

io

ns/C

a2+)

OR

Mg2+

has

a g

reat

er c

harg

e de

nsity

ther

efor

e th

e at

tract

ion

betw

een

Mg2+

and

Cl− is

gre

ater

(th

an b

etw

een

Ca2+

and

Cl– )

3 O

RA

thro

ugho

ut

ALLO

W ‘c

harg

e de

nsity

’ her

e on

ly

ALLO

W m

agne

sium

/Mg

is s

mal

ler

DO

NO

T AL

LOW

Mg2+

has

a sm

alle

r ato

mic

ra

dius

DO

NO

T AL

LOW

chl

orin

e io

ns

DO

NO

T AL

LOW

Mg

has

grea

ter a

ttrac

tion

ALLO

W ‘a

ttrac

ts w

ith m

ore

forc

e’ fo

r gre

ater

at

tract

ion

but D

O N

OT

ALLO

W ‘g

reat

er fo

rce’

(cou

ld b

e re

puls

ion)

(c)

(i)

F

B

G

E

D

FIVE

cor

rect

FO

UR

cor

rect

TH

REE

cor

rect

3 AL

LOW

1450

73

6

G

76

–642

IF

onl

y on

e or

two

corr

ect,

awar

d 0

mar

ks.

(ii)

−642

− (+

76 +

(2 ×

150

) + 7

36 +

145

0 +

(2 ×

−34

9) )

−6

42 −

186

4 = −

2506

(k

J m

ol−1

)

2 AL

LOW

for 1

mar

k:

−270

5 (2

x 1

50 a

nd 2

x 3

49 n

ot u

sed

for Cl)

−235

6 (2

x 1

50 n

ot u

sed

for Cl)

−285

5 (2

x 3

49 n

ot u

sed

for Cl)

+250

6 (w

rong

sig

n)

DO

NO

T AL

LOW

any

oth

er a

nsw

ers

Spe

cimen

PMT

H43

2/01

M

ark

Sche

me

June

20X

X

14

Que

stio

n An

swer

M

arks

G

uida

nce

(d

)*

P

leas

e re

fer t

o th

e m

arki

ng in

stru

ctio

ns o

n pa

ge 4

of t

his

mar

k sc

hem

e fo

r gui

danc

e on

how

to m

ark

this

que

stio

n.

Leve

l 3 (5

–6 m

arks

) D

escr

ibes

and

exp

lain

s co

ncis

ely

the

trend

in re

activ

ity o

f th

e ha

loge

ns

AND

Fu

ll ob

serv

atio

ns o

f red

ox re

actio

ns b

acke

d up

by

at le

ast

two

equa

tions

Th

ere

is a

wel

l-dev

elop

ed e

xpla

natio

n w

hich

is c

lear

and

lo

gica

lly s

truct

ured

. The

obs

erva

tions

and

equ

atio

ns a

re

rele

vant

to th

ose

trend

s ex

plai

ned.

C

lear

and

con

fiden

t kno

wle

dge

of re

leva

nt te

chni

cal

lang

uage

. Le

vel 2

(3–4

mar

ks)

Des

crib

es a

nd e

xpla

ins

the

trend

in re

activ

ity o

f the

ha

loge

ns

AND

Is

abl

e to

reca

ll a

redo

x re

actio

n by

sui

tabl

e ob

serv

atio

ns

and

corre

ctly

link

to a

n eq

uatio

n Th

ere

is a

n ex

plan

atio

n w

ith s

ome

stru

ctur

e. T

he

obse

rvat

ions

and

equ

atio

ns a

re in

the

mos

t-par

t rel

evan

t to

the

trend

exp

lain

ed.

Sou

nd g

rasp

of r

elev

ant t

echn

ical

lang

uage

. Le

vel 1

(1–2

mar

ks)

Des

crib

es th

e tre

nd in

reac

tivity

of t

he h

alog

ens

with

som

e at

tem

pt a

t exp

lana

tion

AN

D

Is a

ble

to re

call

a re

dox

reac

tion

eith

er b

y su

itabl

e ob

serv

atio

n or

by

equa

tion

6 In

dica

tive

scie

ntifi

c po

ints

may

incl

ude:

Tr

end

in re

activ

ity

• M

ore

shel

ls o

r inc

reas

ing

radi

us d

own

the

grou

p •

Incr

ease

d sh

ield

ing

dow

n th

e gr

oup

• M

ore

diffi

cult

to g

ain

an e

lect

ron

O

bser

vatio

ns

• R

eact

ion

of Cl 2

or B

r 2 w

ith I– : o

rang

e/br

own

solu

tion

OR

pur

ple

in o

rgan

ic

• R

eact

ion

of Cl 2

with

Br– : y

ello

w s

olut

ion

OR

or

ange

in o

rgan

ic

Rea

ctio

n eq

uatio

ns

• Cl 2

+ 2B

r– →

Br 2

+ 2

Cl–

•

Cl 2

+ 2I

– →

I 2 +

2Cl–

OR

Br 2

+ 2

I– →

I2 +

2Br

–

• O

rder

of r

eact

ivity

link

ed to

obs

erva

tions

Specim

en

PMT

H43

2/01

M

ark

Sche

me

June

20X

X

15

Que

stio

n An

swer

M

arks

G

uida

nce

The

info

rmat

ion

abou

t the

tren

d is

bas

ic a

nd c

omm

unic

ated

in

an

unst

ruct

ured

way

. The

info

rmat

ion

is s

uppo

rted

by

only

obs

erva

tion

or e

quat

ion

and

the

rela

tions

hip

to th

e tre

nd m

ay n

ot b

e cl

ear.

B

asic

gra

sp o

f rel

evan

t tec

hnic

al la

ngua

ge

0 m

arks

N

o re

spon

se o

r no

resp

onse

wor

thy

of c

redi

t.

Tot

al

16

Specim

en

PMT

H43

2/01

M

ark

Sche

me

June

20X

X

16

Que

stio

n An

swer

M

arks

G

uida

nce

20

(a)

[H

+ ] = 1

0–pH =

10–2

.19 =

6.4

6 1

0–3 (m

ol d

m–3

)

[C

H3C

H(O

H)C

OO

H]

= [H

+ ]2

Ka

=

1.38

1

0–4(6

.46

10–3

)2

= 0

.030

2 (m

ol d

m–3

)

n(

CH

3CH

(OH

)CO

OH

) = 0

.302

× 2

50 =

0.0

755

mol

100

0 M

ass

of C

H3C

H(O

H)C

OO

H =

0.0

755 ×

90 =

6.8

0 g

Dis

solv

e 6.

80 g

of t

he s

olid

in d

istil

led

wat

er (l

ess

than

250

cm

3 ) in

a be

aker

(then

) tra

nsfe

r the

sol

utio

n to

a 2

50 c

m3 vo

lum

etric

flas

k AN

D

ensu

re th

at a

ll so

lutio

n is

was

hed

out o

f bea

ker (

was

hing

s tra

nsfe

rred

to v

olum

etric

flas

k)

(th

en) m

ake

solu

tion

up to

250

cm

3 with

dis

tille

d w

ater

AN

D

ensu

re th

orou

gh m

ixin

g by

inve

rting

the

flask

sev

eral

tim

es

8 AL

LOW

5 m

arks

for 6

.80

g th

roug

h an

y ca

lcul

atio

n.

ALLO

W E

CF

for i

ncor

rect

cal

cula

tion

of m

ass.

M

ass

used

mus

t be

linke

d to

cal

cula

tion.

(b

)

CH

3CH

(OH

)CO

O– +

CH

3CH

2CH

2CO

OH

2+

CH

3CH

(OH

)CO

OH

AN

D C

H3C

H(O

H)C

OO

− C

H3C

H2C

H2C

OO

H A

ND

CH

3CH

2CH

2CO

OH

2+ B

oth

pairs

iden

tifie

d

2 St

ate

sym

bols

NO

T re

quire

d AL

LOW

labe

ls ‘a

cid

1’, ‘

base

1’ e

tc.

ALLO

W E

CF

for s

econ

d m

ark

Specim

en

PMT

H43

2/01

M

ark

Sche

me

June

20X

X

17

Que

stio

n An

swer

M

arks

G

uida

nce

(c

) (i)

[H

+ ] = 1

× 1

0–14

= 5

.405

× 1

0–14

(Use

of K

w)

0.1

85

pH =

–lo

g(5.

405 ×

10–1

4 ) =

13.2

7

2 AL

LOW

5.4

0540

5405

× 1

0–14 a

nd c

orre

ct

roun

ding

to 5

.4 ×

10–1

4 AL

LOW

alte

rnat

ive

appr

oach

usi

ng p

OH

: pO

H =

–lo

g(0.

185)

= 0

.73

pH =

14

– 0.

73 =

13.

27

Cor

rect

ans

wer

sco

res

BO

TH m

arks

AL

LOW

13.

267

(ii

) n(

A– ) = 9

.25 ×

10–3

(mol

)

n(H

A) =

0.0

165 −

9.25

× 1

0–3 =

7.2

5 ×

10–3

(mol

)

[H+ ] =

Ka ×

[HA]

[A− ]

pH =

–lo

g(1.

5 ×

10−5

× 0

.058

) = 4

.93

0.07

4

OR

pH

= –

log(

1.5 ×

10−5

×

12510

25.910

00

12510

25.710

0033 −−

) = 4

.93

Fina

l mar

k al

so v

ia H

ende

rson

–Has

selb

alch

equ

atio

n:

pH =

pK

a – lo

g =

4.8

2 –

(–0.

11) =

4.9

3

OR

pH

= p

Ka +

log

= 4

.82

+ 0.

11 =

4.9

3

4 AL

LOW

HA/

acid

and

A– /s

alt t

hrou

ghou

t for

bu

tano

ate

and

buta

noic

aci

d AL

LOW

pK

a = –

log

Ka O

R –

log

1.5 ×

10–3

OR

4.

82

ALLO

W E

CF

from

inco

rrect

val

ues

of n

(A– ) o

r n(

HA)

ALLO

W p

H =

–lo

g(1.

5 ×

10−5

×33

1025.9

1025.7

−−

) =

4.93

To

tal

16

Spe

cimen

PMT

H43

2/01

M

ark

Sche

me

June

20X

X

18

Que

stio

n An

swer

M

arks

G

uida

nce

21

(a)

(i)

H

alf-c

ells

(2 m

arks

) Ag

(s) a

nd 1

mol

dm

–3 A

g+ (aq)

3

1 m

ol d

m–3

Fe2+

(aq)

AN

D 1

mol

dm

−3 F

e3+(a

q) A

ND

Pt m

etal

3

C

ompl

ete

circ

uit (

1 m

ark)

sa

lt br

idge

AN

D v

oltm

eter

AN

D w

ires 3

St

anda

rd c

ondi

tions

(1 m

ark)

29

8 K

/ 25

ºC A

ND

100

kPa

/ 10

1 kP

a pr

essu

re 3

4 AL

LOW

1 a

tm

(ii)

(Ele

ctro

de p

oten

tial o

f) Ag

+ /Ag

beco

mes

mor

e po

sitiv

e

3

ther

efor

e, E

cell b

ecom

es s

mal

ler O

R le

ss p

ositi

ve. 3

2 AL

LOW

equ

ilibriu

m A

g/Ag

+ shi

fts to

righ

t AL

LOW

mor

e ne

gativ

e 2nd

mar

k on

ly a

vaila

ble

if de

duce

d fro

m 1

st m

ark

ALLO

W E

CF

for 2

nd m

ark

Specim

en

PMT

H43

2/01

M

ark

Sche

me

June

20X

X

19

Que

stio

n An

swer

M

arks

G

uida

nce

(b

)

Ce3+

and

Zn2+

3

1

(c

)

Mn2+

, H2O

, Fe3+

, Br 2

Th

ree

spec

ies

corre

ct 3

Fo

ur s

peci

es c

orre

ct 3

2

To

tal

9

Specim

en

PMT

H43

2/01

M

ark

Sche

me

June

20X

X

20

Que

stio

n An

swer

M

arks

G

uida

nce

22

(a)

1.

n(A

gCl)

form

ed =

7.6

95

= 0

.053

62 (m

ol) 3

143

.5

2. 0

.018

0 m

ol o

f B fo

rms

0.05

362

mol

of Cl−

N

o of

Cl– io

ns in

form

ula

of B

= 0

.053

62 =

3 3

0

.018

0 3.

Mol

ar m

ass

of B

= 2

.856

=

158.

7 (g

mol

−1) 3

0.01

80

1

58.7

− (3

× 3

5.5)

= 5

2.2

whi

ch is

chr

omiu

m 3

4.

n(H

2O)

= 1.

944

= 0

.108

(mol

)

18

0

.018

0 m

ol C

rCl 3:

0.1

08 m

ol H

2O

O

R 1

mol

CrCl 3:

6 m

ol H

2O 3

A

CrCl 3•

6H2O

(fro

m p

oint

s 2,

3 a

nd 4

) 3

B

CrCl 3

(fro

m p

oint

s 2

and

3) 3

D

[Cr(H

2O) 6

]3+ (f

rom

det

erm

inat

ion

of A

and

und

erst

andi

ng o

f re

actio

n w

ith w

ater

) 3

E

Cr(O

H) 3

(fro

m u

nder

stan

ding

of r

eact

ion

of D

with

aqu

eous

hy

drox

ide)

3

9 AL

LOW

Alte

rnat

ive

wor

king

thro

ugho

ut

Specim

en

PMT

H43

2/01

M

ark

Sche

me

June

20X

X

21

Que

stio

n An

swer

M

arks

G

uida

nce

(b

)*

P

leas

e re

fer t

o th

e m

arki

ng in

stru

ctio

ns o

n pa

ge 4

of

this

mar

k sc

hem

e fo

r gui

danc

e on

how

to m

ark

this

qu

estio

n.

Leve

l 3 (5

–6 m

arks

) Li

nks

toge

ther

nam

es o

f sha

pes

with

cor

rect

3-D

di

agra

ms

AN

D

Appr

ecia

tes

the

two

diffe

rent

type

s of

isom

eris

m a

nd

labe

ls d

iagr

ams

appr

opria

tely

Th

ere

is a

wel

l-dev

elop

ed li

ne o

f rea

soni

ng w

hich

is

clea

r and

logi

cally

stru

ctur

ed. T

he in

form

atio

n pr

esen

ted

is re

leva

nt a

nd s

ubst

antia

ted.

D

emon

stra

tes

clea

r and

con

fiden

t kno

wle

dge

of

rele

vant

tech

nica

l lan

guag

e us

ing

the

term

s •

non-

supe

rimpo

sabl

e m

irror

imag

es w

ithin

opt

ical

is

omer

ism

•

oppo

site

and

adj

acen

t/sam

e si

de in

cis

–tra

ns

Leve

l 2 (3

–4 m

arks

) N

ames

and

labe

ls a

t lea

st tw

o of

the

shap

es

appr

opria

tely

giv

ing

3-D

dia

gram

s

AND

Ap

prec

iate

s th

at tw

o ty

pes

of is

omer

ism

exi

st in

tra

nsiti

on m

etal

che

mis

try, g

ives

dia

gram

s to

illu

stra

te

at le

ast o

ne p

air o

f iso

mer

s an

d na

mes

them

cor

rect

ly

Ther

e is

a li

ne o

f rea

soni

ng p

rese

nted

with

som

e st

ruct

ure.

The

info

rmat

ion

pres

ente

d is

in th

e m

ost-p

art

rele

vant

and

sup

porte

d by

som

e ev

iden

ce.

Ans

wer

s qu

estio

n w

ith a

sou

nd g

rasp

of r

elev

ant

tech

nica

l lan

guag

e us

ing

the

term

s

6 In

dica

tive

scie

ntifi

c po

ints

may

incl

ude:

Sh

apes

of c

ompl

ex io

ns

• si

x co

ordi

nate

bon

ds: o

ctah

edra

l •

four

coo

rdin

ate

bond

s: te

trahe

dral

or s

quar

e pl

anar

•

3-D

dia

gram

s w

ith c

harg

es li

nked

to s

hape

s

CuOH

2

OH

2

H2O

OH

2H

2O

OH

2

2+

CuCl

Cl

Cl

Cl

2-

Pt

H3N

NH

3

Cl

Cl

Oct

ahed

ral

Tetra

hedr

alSq

uare

Plan

ar

cis–

tran

s is

omer

ism

•

foun

d in

oct

ahed

ral a

nd s

quar

e pl

anar

com

plex

es

• tra

ns –

opp

osite

; cis

– a

djac

ent /

sam

e si

de

• 3-

D d

iagr

ams

to il

lust

rate

O

R

Specim

en

PMT

H43

2/01

M

ark

Sche

me

June

20X

X

22

Que

stio

n An

swer

M

arks

G

uida

nce

• te

trahe

dral

, oct

ahed

ral

• ci

s–tra

ns O

R o

ptic

al

Leve

l 1 (1

–2 m

arks

) N

ames

and

dra

ws

stru

ctur

es o

f tw

o of

the

shap

es

AND

Ap

prec

iate

s on

e ty

pe o

f iso

mer

ism

that

can

be

seen

in

trans

ition

met

al c

hem

istry

Th

e in

form

atio

n is

bas

ic a

nd c

omm

unic

ated

in a

n un

stru

ctur

ed w

ay. T

he in

form

atio

n is

sup

porte

d by

lim

ited

evid

ence

and

the

rela

tions

hip

to th

e ev

iden

ce

may

not

be

clea

r.

Ans

wer

s qu

estio

n w

ith a

bas

ic g

rasp

of r

elev

ant

tech

nica

l lan

guag

e •

links

oct

ahed

ral t

o si

x lig

ands

and

tetra

hedr

al to

four

lig

ands

eith

er in

wor

d or

by

diag

ram

•

corr

ectly

link

s on

e ty

pe o

f iso

mer

ism

to a

stru

ctur

e 0

mar

ks

No

resp

onse

or n

o re

spon

se w

orth

y of

cre

dit.

Opt

ical

isom

eris

m

• Fo

und

in o

ctah

edra

l com

plex

es w

hen

bide

ntat

e lig

ands

are

pre

sent

•

Isom

ers

are

non-

supe

rimpo

sabl

e m

irror

imag

es

• 3-

D d

iagr

ams

to il

lust

rate

CrCl

NH

2

NH

2

N H2

H2NC

lC

H2

CH

2

H2C

C H2

2+

Cr

Cl

H2N

NH

2

N H2

NH

2

Cl

H2C H

2C

CH

2

C H2

2+

O

R

NiNH

2

NH

2

NH

2

N H2

H2N

N2H

H2

CH

2C

CH

2

CH

2

H2C

C H2

2+

Ni

H2N H2N

NH

2

N H2

NH

2

HN

2

H2

CC

H2

H2C H

2C

CH

2

C H2

2+

To

tal

15

Specim

en

PMT