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