Practical

Question 1

Number of moles

Answer 1

M*V

Question 2

2nd qs usually

Answer 2

Mole ratio method

Question 3

If NaOH(Alkali) in the burrette(Fa1)

Answer 3

27-29

Question 4

If H2SO4(acid) is in the burette (Fa2)

Answer 4

23-25

Question 5

So ratio between

Answer 5

FA1: FA2 (1:18 conc. ratio)

Question 6

NaOH: H2SO4

Answer 6

(1:1)

Question 7

Remove the funnel as so as you pour

Answer 7

the acid into the burette

Question 8

First rinse burette w water

Answer 8

then rinse w acid

Question 9

show how you work-out the

Answer 9

average

Question 10

After you add acid to burette

Answer 10

allow some acid to flow and make it zero – due to air gaps.

Question 11

CALCULATING % UNCERTAINTY
Burette

Answer 11

 Take least count of burette (0.1)
 Find error (0.1/2 = 0.05)
 Calculate % error ( (error/value) *2) *100
 =0.4(usual range)

Question 12

calculating % uncertainity of Balance

Answer 12

 Least count (0.01)
 Error (0.005 )
 % error same formula (remember *2)
 *2 because initial and final

Question 13

Why does burette have a higher % uncertainty than pipette?

Answer 13

 Burette least count is 0.1
 Pipette least count is 0.01
 However the burette is used twice therefor increasing its % uncertainty

Question 14

Student is incorrect AND explanation given:

Answer 14

burette error = 2  0.05 (which is >0.06 / so 0.40% >
0.24%)

Question 15

Answer 15

Question 16

FA7

Answer 16

Ketone

Question 17

FA8

Answer 17

ALDEHYDE

Question 18

FA9

Answer 18

CARBOXYLIC ACID

Question 19

CuSO4

Answer 19

(dissolve in an alkali (NaOH), warm it) (Fehling’s reagent)
 Blue to brown for aldehyde (FA8)
 For FA7 and FA9 (it remains blue)

Question 20

Sodium Carbonate

Answer 20

 FA9: colorless gas evolved turns lime water milky
 Doesn’t rct with FA7 or FA8

Question 21

KMnO4 (not acidified)

Answer 21

 So add acid to acidify it
 Add water to dilute
 Purple to colorless FA8 ONLY
 Other remain same

Question 22

2,4 – DNPH

Answer 22

 FA7, FA8 orange ppt obtained
 FA9 remains colorless

Question 23

SALT ANALYSIS

Answer 23

 FA5 in a boiling tube
 Add 3-4 cm3 of HNO3
 Write observations
 Brisk effervescence

Question 24

FA5 

Answer 24

ZnCO3 + KI

Question 25

FA6 

Answer 25

FA5 + dil.Acid
(white fumes, salt melts, color change)

Question 26

Take FA5 and add acid

Answer 26

and label as FA6

Question 27

experiments for Fa5

Answer 27

Question 28

IIonic eqn for AgNO3 and iodine

Answer 28

Question 29

If we dissolve the FA5 in water

Answer 29

cation is Zinc

Question 30

If we dissolve the FA5 in acid

Answer 30

cation is Magnesium

Question 31

ionic eqn for iodine

Answer 31

Question 32

enthalpy changes

Answer 32

Question 33

enthalpy change words

Answer 33

 Measure mass of reagent bottle with FA4
 Initial temperature of distilled water
 Final temperature of distilled water
 Mass of empty reagent bottle
 Mass of FA4
 Temperature change (will be negative – endothermic rnc)