Thursday, October 28, 2010

F4 Chap 9: Activity 4 (Answer)



Saturday, October 2, 2010

Correction on SBP Trial Paper

Pembetulan Jawapan
paper 1 : 
4. D
36. D

Paper 2: 5(b) Brown {not purple}
Tambahan pembetulan Esei
9(b) for 0.001
change H+ to OH- for point 4 and 5
6. hydrogen , replace Oxygen

10(a)(i)
1. Exp I, II, III

Friday, August 27, 2010

ALL CHEMISTRY TRIAL PAPERS 2010

Dear F5 students,


Here are the trial papers from other state. I'll upload them when i get the new set. Do check it out.


Sekolah Berasrama Penuh (SBP) - Paper 1 + 2 + 3 (Question+Answer)
Kedah Trial - Paper 1 + 2 + 3 (Question+Answer)
Terengganu Trial  (Paper 1 + Paper 2 + Paper 3 + Answer)
Perak (P1+P2+P3+Answer)
Johor (P1+P2+P3+Answer)
Kelantan (P1+P2+P3+Answer)
Times (Answer)
Perlis (P1+P2+P3+Ans) New (25/9)
Jawab Untuk Jaya 2010 New (30/9)
Pahang (Paper 1 + Paper 2 + Paper 3 + Answer) New (09/10/10)
Penang (Papers + Answers) New 14/10
MARA (P1+P2+P3) New 21/10
Melaka (Set 1 + Answer // Set 2+ Answer)  New 25/10 

Monday, August 16, 2010

Form 4 Chapter 7 (Activity answer)

Activity 12


1
 Standard solution – a solution in which its concentration is accurately  known
5
(a)
  • Calculate the mass of solute needed.
  • Weigh out the exact mass of solute needed in a weighing bottle.
  • Dissolved the solute in a small amount of distilled water.

(b)
·         Wash and rinse the weighing bottle ,small beaker and filter funnel to ensure  no solute remains in any  of the apparatus used.
  • Transfer the dissolved solute into a suitable volumetric flask.

(c)
  • Add more water carefully to the volumetric flask and swirl gently.
  • Shake well to ensure thorough mixing.
(d)
  • Add water slowly by using a dropper to bring the level of the solution to the calibration mark.
  • The volumetric flask is closed tightly and inverted several times to get a uniform or homogenous solution.


Activity 13:


3
(a)
  • Calculate the volume of stock solution required.
(b)
  • Use a pipette to draw up the required volume of stock solution.
(c)
  • Transfer the stock solution to a suitable volumetric flask.
(d)
  • Add water slowly by using a dropper to bring the level of the solution to the calibration mark.
  • The volumetric flask is closed tightly and inverted several times to get a uniform or homogenous solution.


Activity 14:



1

2
3
4
(a) hydrogen dissociation/ionization         b) concentration       
(c) concentration, alkali
Higher, hydrogen
Higher, hydroxide
Decrease, increase
Activity 15



3
(a) 2HNO3   +           Ba(OH)2 (aq)             →          Ba(NO3)2 (aq)      +   H2O  (aq)

(b)  H2SO4   +        2NaOH (aq)             →          Na2SO4 (aq)      +  2H2O  (aq)

(c)  2H3PO4   +        3Ca(OH)2 (aq)          →        Ca3(PO4)2 (aq)      +  6H2O  (aq)

(d)  CH3COOH   +        KOH (aq)           →          CH3COOK (aq)      +  H2O  (aq)
Activity 16



3
Indicator
Colour in solution of:
Acid
Alkali
Red litmus paper
-
blue
Blue litmus paper
red
-
Phenolphthalein
colourless
pink
Methyl orange
red
yellow
Activity 18



1(a)
Initial burette readings: 0.80 cm3, 13.40 cm3, 25.90 cm3
Final burette readings : 13.40 cm3, 25.90 cm3, 38.40 cm3
(b)
Titration No.
I
II
II
Initial burette reading/cm3
0.80
13.40
25.90
Final burette reading/cm3
13.40
25.90
38.40
Volume of acid used/cm3
12.60
12.50
12.50
(c)
Volume of acid used = 12.60 + 12.50 + 12.50
                                                3
                                   = 12.50 cm3
(d)
2 mol dm-3
(e)
6.25 cm3
(f)
Strong acids: hydrochloric acid, sulphuric acid, nitric acid
Weak acids: ethanoic acid, carbonic acid
(g)
Pink to colourless
(h)
Yellow to red
(i)
HCl   +   NaOH         -->     NaCl   +   H2O

Activity 19




1
(a)(i)
Sodium hydroxide/ potassium hydroxide
r: formula
1

    (ii)
-->2NaOH  +  H2SO4           Na2SO4   +   2H2O
/ 2KOH   +  H2SO4   -->        K2SO4   +    2H2O
-         Chemical formulae of reactants and products correct
-         Equation is balanced


1
1

    (iii)
soap
1

     (iv)
Y
1

(b)(i)
W / X

1

    (ii)
-         W is added into sodium carbonate/any metal carbonate stated in a test tube,
-         Gas released turns lime water cloudy

/ - magnesium/zinc  is added into W in a test tube,
- gas released gives a ‘POP’ sound with a lighted splinter
1

1

    (iii)
-         W is a strong acid and X is a weak
-         W completely dissociates in aqueous solution to produce high concentration of hydrogen ions.
    / X dissociates partially in aqueous solution to
       produce low concentration of hydrogen ions.

1

1