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“We must trust to nothing but facts: These are presented to us by Nature, and cannot deceive. We ought, in every instance, to submit our reasoning to the test of experiment, and never to search for truth but by the natural road of experiment and observation.” ― Antoine Lavoisier, Elements of Chemistry

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Saturday, 29 November 2014

Slides: Kinetic Theory of Particle Presentation (ppt)

Here are the slides of Particulate of Matter (Kinetic Theory of Particle)

Link to download : Particulate of Matter - part 1
                               
                                Particulate of Matter - part2

TURNING ON A PIVOT worksheet (ANSWER)

Click to download the document

1. Calculate the moment of this force. Show your working.  



 ANSWER:
Moment = F x D
               = 100N  x  0.3m
               = 30Nm

2.   This system is balanced
 a)      Calculate the size of the clockwise moment
Clockwise moment    = (20N x 3m)  +  (25N x (3m + 1m))
                                    = 60 Nm  + 100 Nm
                                    = 160 Nm

b)      State the size of the anticlockwise moment
Anti-clockwise moment        = X N  x 2m
                                                = 2X m

c)      Calculate the size of force X
      Clockwise moment    =  Anti-clockwise moment
                 160 Nm      =  2X m
                        160 : 2 = X
                                     80 = X


3.  A pivoted uniform bar is in equilibrium under the action of the forces shown.
 What is the magnitude of the force F?
Anti -Clockwise moment  =  Clockwise moment
      10N  x  4m                    =  (F x 2m) + (6N x (2m+2m))
                              40 Nm   =  2F m + 24 Nm
              40 Nm – 24 Nm    = 2F m
                        16 Nm         = 2F m
                     16 Nm : 2 m              = F
                              8 N      = F


4.   A uniform beam AB of mass 20kg and length 3m rests in equilibrium in a horizontal position. The beam is supported by a single pivot at C and a particle of mass 6kg is attached at B.

       Calculate the distance AC.
Assume:    AC is X meter, so CB is (3 – X) meter
Anti -Clockwise moment  =  Clockwise moment
      20 kg  x  X                    =  6 kg  x  (3 – X)
                  20X                    = 18 – 6X
                  20X + 6X           = 18
                              26X        = 18
                                  X        = 18 : 26
                                  X        = 0.69 meter



5.    a uniform metre rule, freely pivoted at a point 20 cm from end P.

The rule is kept horizontal by means of a 120g mass suspended 5.0 cm from end P. Use the principle of moments to help you determine the mass of the metre rule.
Anti -Clockwise moment  =  Clockwise moment
            120 x 15                        =  MASS x 30
                        1800                 = MASS x 30
                        1800 : 30          = MASS

                        60 gram            = MASS


6.   Look at this example of a balanced system

      a)      Calculate the size of the clockwise moment
ANSWER:
Clockwise  Moment = F x D
                                    = 10N  x  4.5m
                                     = 45Nm

b)      State the size of the anticlockwise moment
ANSWER:
Anti-clockwise  Moment       = F x D
                                                = 15N  x  Xm
                                                = 15XNm


c)      Calculate the distance x.         
Clockwise moment      = Anti-clockwise moment
                10N  x  4.5m =  15N  x  Xm
                          45 Nm = 15X Nm
                                  X = 45 : 15
                                  X = 3 m
       

                         

Tuesday, 25 November 2014

WORKSHEET expansion

EXPANSION GRAPHS
Kindly download your assignment by clicking the link below:
http://www.4shared.com/rar/6mPL_1zsce/Documents.html

Thursday, 13 November 2014

PHYSICS: Moment worksheet

1. The diagram shows the electromagnet just above an iron rod, which is pivoted at one end. A box is hanging from the other end.

Ignore the mass of the rod in the following questions.

a) What is the mass of the box?
b) What is the force produced by the electromagnet?

2.   A beam of wood is balanced on a brick. A girl  stands at a point 50 cm from the centre. Ten 2 kg masses are placed on the plank 2.5 m from  the centre on the opposite side and the beam balances. What is the mass of the girl?


3. Henry uses the light seesaw shown below to measure Mary's mass.

            Use the information in the diagram to calculate Mary's mass. Show your working.

  4. An empty wheelbarrow, which weighs 65.5 N. The operator pulls upwards on the handles with a force of 20 N to keep the handles horizontal. The point marked M is the centre of mass of the wheelbarrow.

Determine: the distance between points A and M.

Review: Acids and Bases for Checkpoint


Acids
¢  An acid is a compound/substance that produces hydrogen ions (H+) when dissolved in water
¢  Acids taste sour.
¢  Acids turn indicators red
¢  An acid has pH lower than 7

Bases
¢  Bases are ionic compounds that produce hydroxide ions (OH-) when dissolved in water .
¢  Bases taste bitter and feel slippery
¢  Bases turn indicators blue
¢  Bases release hydroxide ions in water solutions (the more released, the stronger the base)
¢  Has pH more than 7; pH range  7-14

Indicators
¢  Indicators are weak organic acids or bases which have the property of changing color in solution when the hydrogen ion concentration reaches a definite value.
¢  The most used indicator is litmus (extracted from lichens)
¢  Blue paper litmus changes color to red in acid solution
¢  Red paper litmus turns blue in alkali solution
Acids Affect Indicators, by changing their color

Blue litmus paper turns  red  in contact with an acid  (and red paper stays red).

Bases Affect Indicators

Red litmus paper turns  blue  in contact with a base (and blue paper stays blue).
Phenolphthalein turns purple in a base.
The pH scale
¢  The pH scale is a measure of the hydrogen ion concentration, the scale runs from 0 to 14
¢  Acids have pH less than 7, more strength acid, the lower the pH
¢  Neutral substances have a pH of 7
¢  Bases have pH 7 to 14, more alkaline in solution, the higher the pH
¢  The pH of a solution can be measured by universal indicator paper and pH meter

More on pH
¢  If you add an acid to water, the concentration of hydrogen ions increases and the concentration of hydroxide decreases. 
¢  The lower the pH value, the greater the hydrogen ion concentration.
¢  If you add base to water the concentration of hydroxide increases and the hydrogen ion concentration decreases.

¢  The higher the pH value, the lower the hydrogen ion concentration.

Common Acids and Bases

Acids
¢  Hydrochloric acid   HCl
¢  Nitric acid                            HNO3
¢  Sulphuric acid                    H2SO4
Bases
¢  Sodium hydroxide   NaOH
¢  Calcium hydroxide Ca(OH)2
¢  Magnesium hydroxide   Mg(OH)2
¢  Ammonium hydroxide  NH4OH


WORKSHEET


1.       Name 2 acids and their uses.

 2.       Name 2 bases and their uses.

 3.       Describe one way you can safely determine whether an unknown solution is an acid or base?

4.     How can an acid be neutralized?

Tuesday, 11 November 2014

Experiment: The Effect of Sulfur Dioxide (IGCSE class)

Guide Questions:

1. What are the sources of sulfur dioxide gas?
2. Describe the effect of sulfur dioxide to our environment?

Monday, 3 November 2014

Monday, 20 October 2014

Particulate of Matter Worksheet

FOR ALL CP1
DO THIS WORKSHEET AS YOUR HW, DO IT IN YOUR EXERCISE BOOK.
UNDERLINE YOUR ANSWER IN PART A WITH RED PEN.
SUBMIT IT ON MONDAY, OCTOBER 27 ON MR. MARKUS DESK. 
GBU


A. Fill in the blank with correct word by choosing the following words: [17]
FAST                 MOBILE             SLIDE             CONSTANLY               IDENTICAL           CHANGED           FIXED SIZES             PARTICLES           SMALL         VIBRATE                        SOLIDS        STRONGER                         SPEEDS                           VAPOR LIQUID                 WEAKER              SPACES              CLOSER               DIFFERENT          GAS

  1. All matter consists of _________ particles. A single drop of water contains more than 30 million _______________ of water.
  2. All particles of one substance are  identical. Particles of different substances are__________
  3. The ______________ between the particles are very large, compared to the particle ____________.
  4. A single drop of water can be ____________ to water vapor that occupies a volume 1700 x greater.
  5. The particles in matter are attracted to each other with _____________ or ________________ forces. The ______________ the particles the stronger the attractive forces.
  6. Attractive forces are much stronger in solid  than in __________ or ____________since particles are much closer together.
  7. All particles of matter are _____________ in motion.
  8. Particles in solid _____________ in ____________ positions.
  9. Liquid particles exist in clumps that can ______________ or roll by each other.
  10. Particles of gas are very ___________ moving. Air particles travel at ___________ of around 45 m/s.

B. Answer Briefly...
1. Name the physical changing below, and state the process involved whether absorb heat (gain heat) or release heat (heat is out)
   a. freezing
   b. melting
   c. condensing
   d. vaporisation
2. When you take ablock of butter out the fridge, it is quite hard. However, after 15 minutes it is soft enough to spread. Explain.


Friday, 26 September 2014

Chemical Bonding Worksheet

Do these following questions in your exercise book. Submit it on Thursday October 2, 2014


1. What type of bond would be found between the following pairs of elements?
     (a) sulfur and chlorine
     (b) carbon and oxygen
     (c) magnesium and nitrogen
     (d) zinc and copper
2. what force holds the sodium and chlorine together in sodium chloride?
3. Draw diagrams of the covalent bonding in the following elements and compounds (show the outer electrons only in your diagram)
    (a) hydrogen
    (b) fluorine gas
    (c) water
4. Draw diagrams the ionic bonding in the following compounds
    (a) lithium fluoride
    (b) barium oxide
    (c) aluminum chloride

Tuesday, 9 September 2014

Monday, 18 August 2014

Common Lab Apparatus & Techniques Worksheet



ANSWER ALL OF THESE QUESTIONS. (40 marks)
For #1 – 8, Fill in the blank the right or correct apparatus which used for the following: (8 marks)
  1. _________________ Used to transfer liquids into small mouthed containers
  2. _________________ Used to protect eyes
  3. _________________ Used to dispense small amounts of liquids, dropwise
  4. _________________ Used to produce a flame for heating materials
  5. _________________ Used for grabbing hot test tubes
  6. _________________ Worn to protect user from splashes and spills
  7. _________________ Used to transfer dry solids, particularly from original container to scale
  8. _________________ Used to measure temperature.

  1. Name and draw the diagram of apparatus used for:

  1. heating (4 apparatus) (8 marks)
  2. measuring volume of liquids (4 apparatus) (8 marks)
  3. transferring liquid (4 apparatus) (8 marks)
  4. transferring solids (4 apparatus) (8 marks)

Tuesday, 22 July 2014

Friday, 30 May 2014

TYPES OF REACTIONS-BALANCING CHEMICAL EQUATIONS-MOLARITY WORKSHEET

Here is a worksheet for types of reactions-balancing chemical equations-molarity
click to download the paper

Wednesday, 28 May 2014

QUIZ CP2 : QUESTIONS + ANSWERS

Friday, 23 May 2014

Acid and Base Quiz

Tuesday, 13 May 2014

Stoichiometry of Solutions Presentation (ppt)

Monday, 5 May 2014

Exercise for Checkpoint

Wednesday, 2 April 2014

Friday, 28 March 2014

CP1 HOMEWORK-part2

Here is your homework part 2, click here to download
Submission: submit both of your homeworks (part1 and part2) on Mr. Markus desk on March, 10

CP1 : HOMEWORK-part 1

To download your homework, kindly click here

ANIONS AND CATIONS LIST

simple ions:
Hydride
H-
Oxide
O2-
Fluoride
F-
Sulfide
S2-
Chloride
Cl-
Nitride
N3-
Bromide
Br-
Iodide
I-
Oxoanions:
Arsenate
AsO43-
Phosphate
PO43-
Arsenite
AsO33-
Hydrogen phosphate
HPO42-
Dihydrogen phosphate
H2PO4-
Sulfate
SO42-
Nitrate
NO3-
Hydrogen sulfate
HSO4-
Nitrite
NO2-
Thiosulfate
S2O32-
Sulfite
SO32-
Perchlorate
ClO4-
Iodate
IO3-
Chlorate
ClO3-
Bromate
BrO3-
Chlorite
ClO2-
Hypochlorite
OCl-
Hypobromite
OBr-
Carbonate
CO32-
Chromate
CrO42-
Hydrogen carbonate
or Bicarbonate
HCO3-
Dichromate
Cr2O72-
Anions from Organic Acids:
Acetate
CH3COO-
formate
HCOO-

Others:
Cyanide
CN-
Amide
NH2-
Cyanate
OCN-
Peroxide
O22-
Thiocyanate
SCN-
Oxalate
C2O42-
Hydroxide
OH-
Permanganate
MnO4-
Common Cations: (ions grouped by charge)
Name
Formula
Other name(s)
Ammonium
NH4+
Barium
Ba+2
Calcium
Ca+2
Chromium(II)
Cr+2
Chromous
Chromium(III)
Cr+3
Chromic
Copper(I)
Cu+
Cuprous
Copper(II)
Cu+2
Cupric
Iron(II)
Fe+2
Ferrous
Iron(III)
Fe+3
Ferric
Hydrogen
H+
Hydronium
H3O+
Lead(II)
Pb+2
Magnesium
Mg+2
Manganese(II)
Mn+2
Manganous
Manganese(III)
Mn+3
Manganic
Mercury(I)
Hg2+2
Mercurous
Mercury(II)
Hg+2
Mercuric
Nitronium
NO2+
Strontium
Sr+2
Tin(II)
Sn+2
Stannous
Tin(IV)
Sn+4
Stannic