SKEMA SBP PAPER 2 ESSAY PART C NO. 9, 10. BY USING SUITABLE EXAMPLES, STATE 2 APPLICATIONS OF NEUTRALIZATION IN DAILY LIFE [ 4 MARKS] Essay part c)

SKEMA SBP PAPER 2ESSAY PART C

NO. 9, 10

BY USING SUITABLE EXAMPLES, STATE 2 APPLICATIONS OF

NEUTRALIZATION IN DAILY LIFE [ 4 MARKS]

Essay part c)

1. Use ammonia to prevent latex from coagulate

4. Use antacid /sodium hydrogen carbonate to neutralise acid in stomach of gastric patients

2. Use lime /quick lime (calcium oxide)/ slaked lime (calcium hydroxide), chalk (calcium carbonate) to neutralise acidic soil

3. Use magnesium hydroxide / toothpaste to neutralise acid produced by bacteria in our mouth

•RUB BEE STING OR ANT STINGS ( WHICH IS ACIDIC)WITH CALCIUM CARBONATE

•RUB WASP STING ( WHICH IS ALKALINE ) WITH VINEGAR

Any 2 applications ( 4 marks)

B) BY USING ONE NAMED EXAMPLE FOR EACH ALKALI, EXPLAIN WHY THE PH VALUES OF THE ALKALIS ARE DIFFERENT ( 6 MARKS)

NOTES ON PH VALUES AND CONC OF H + IONS AND OH - ION

•THE HIGHER THE CONC OF H+ ION, THE ……..THE PH VALUE

•SO STRONG ACID HAS A … … PH VALUE THAN A WEAK ACID OF THE SAME CONCENTRATION

•THE HIGHER THE CONC OF OH- ION, THE …..THE PH VALUE

•SO STRONG ALKALI HAS A ……. PH VALUE THAN A WEAK ALKALI OF THE SAME CONCENTRATION

lower

higher

higher

lower

Example of R ; sodium hydroxide solution/ litium hydroxide solution/ potassium hydroxide solution (any strong alkali)R ionised completely in water and produced high concentration of OH- ions

Example of Q : ammonia aqueous / solution ( weak alkali)

Q ionised partially in water and produce low concentration of OH- ions the higher the concentration of OH – ions in R the higher the pH values

SOLUTION X AND SOLUTION Y ARE USED TO PREPARE BARIUM CARBONATE

SALTDESCRIBE THE PREPARATION OF BARIUM CARBONATE SALT IN THE

LABORATORY[ 10 MARKS]

Barium carbonate is insoluble salt

NOTES – SOLUBLE AND INSOLUBLE SALTS

Soluble Insoluble sulphatesChlorides

carbonates

nitrates

All except PCB, PbSO4, CaSO4, BaSO4All except PAH, PbCl2, AgCl, HgCl2

KAN, K2CO3, Na2CO3, (NH4)2CO3

All except

All

NOTES ON METHODS TO PREPARE SALTS

KAN salts

Soluble salts

Not KAN salts

Insoluble salts

Titration methodHot acid + excess solid

( metal/metal oxide/metal

hydroxide/metal carbonates) method

Precipitation or double decomposition

STATE WHICH METHOD TO USE FOR THE PREPARATION OF THESE SALTS

BARIUM SULPHATE Precipitation

Sodium nitrate Titration

Zinc chloride Hot acid + excess ( zinc/

zinc oxide/ zinc hydroxide/ zinc carbonate

Copper(II) sulphate

Silver chloride

Potassium sulphate

Hot acid + excess ( copper oxide/ copper(II)

hydroxide/ copper(II) carbonate

Precipitation

Titration

notes

TO PREPARE SALT

SOLUBLE SALT INSOLUBLE SALT

KAN SALTS NOT KAN SALTS

notes

solution 1 is barium nitrate solution 50 cm3

of 1.0 moldm -3

Soln 2 is sodium carbonate solution 50 cm3

of 1.0 moldm -3Pour solution 1 into a beaker

Add solution 2 into the beaker with solution 1

Stir the mixture using glass rod

Filter the mixture

Rinse the residue with distilled water

Dry the residue in between sheet of filter papers to dry

EQUATION

•Ba(NO3) 2 + Na2CO3 BaCO3 +

2NaNO3

10 A)COMPOUND A AND B BURNT COMPLETELY IN OXYGEN O PRODUCE CARBON DIOXIDE

AND WATER

•A) NAME COMPOUND B

•WHY COMPOUND B PRODUCE MORE SOOT [ 4 MARKS]

1- hexene or hex-1-ene

% of C in compound B = 6C/ C6H12 =12x6/ 6(12) + 12(1) = 72/84= 86%

% of C in compound B is more than in compound A

% of C in comp A = 6C/ C6H14 =12x6/ 6(12) + 14(1) = 72/86= 84%

NOTES PHYSICAL PROPERTIES OF ORGANIC COMPOUND

•ETHANE OR ETHENE• Colourless gas , • low mp and bp, • NOT dissolve in

water, • NOT conduct

electricity

NOTES PHYSICAL PROPERTIES OF ORGANIC COMPOUND

•ETHANOL • Colourless liquid• Volatile liquid• low mp and bp, • Miscible in water, • NOT conduct

electricity

PHYSICAL PROPERTIES OF ORGANIC COMPOUND

•ETHANOIC

ACID

• Colourless liquid• Volatile liquid• low mp and bp, • dissolve in water, • NOT conduct electricity in

glacial form, but conduct electricity in aqueous form

NOTES

PHYSICAL PROPERTIES OF ORGANIC COMPOUND

•ETHYL ETHANOATE • Colourless liquid, • Sweet smelling • low mp and bp, • volatile liquid, • NOT dissolve in

water, • NOT conduct

electricity• Floats on water • Less dense than

water

NOTES

B) STATE ONE PHYSICAL PROPERTY OF COMPOUND K. DESCRIBE BRIEFLY A CHEMICAL TEST TO

DIFFERENTIATE BETWEEN COMPOUND J AND COMPOUND K [ 6 MARKS]

•MISCIBLE IN WATER

•LOW MELTING POINT AND BOILING POINT

•DOES NOT CONDUCT ELECTRICITY

•VOLATILE COLOURLESS LIQUID

•COMPOUND K IS ETHANOL

EASY CHEMICAL TEST FOR CARBON COMPOUNDS

•ALKENE

•ALCOHOL

•CARBOXYLIC

ACID

notesAdd bromine water,

brown bromine colour decolourise

Add acidified K2Cr2O7 and warmOrange colour change to green

Add in a few marble chips, pass the gas through lime water, turns milky

DESCRIBE BRIEFLY A CHEMICAL TEST TO DIFFERENTIATE BETWEEN COMPOUND J AND

COMPOUND K [ 6 MARKS]•Pour 2 cm3 of compound J into a test tube

•Add a few drops of acidified

potassium dichromate(VI) solution

•Warm slowly , Observe colour change

•Repeat the procedure above with compound K

• If acidified potassium dichromate solution change from orange to green, then the compound is alcohol

J is ethanoic acidK is ethanol

DESCRIBE HOW TO PREPARE AN ALKENE FROM A NAMED ALCOHOL THROUGH DEHYDRATION PROCESS. IN YOUR DESCRIPTION,

INCLUDE THE DIAGRAM OF THE APPARATUS SET UP AND BALANCED CHEMICAL EQUATION FOR THE REACTION [ 10 MARKS]

•2. Place glass wool in a boiling tube

•3. Add a few drops of ethanol to the glass wool

•4. Clamp the boiling tube horizontally

•5. Place a porcelain chips in the middle of the boiling tube

•6. Heat the porcelain chips strongly

•7. Heat the ethanol

•8. Collect the gas produced in a test tube

•9. Equation: C2H5OH → C2H4 + H2O

HOMEWORK

•1) COMPLETE SBP – PAPER 3 – ALL QUESTIONS FOR TOMORROW AT 10 PAGI

•2) READ UP PLANNING EXPERIMENT- 6 EXAMPLES WITH ANSWERS

•3) READ UP ESSAY AND ANSWERS MARA SECTION B AND C