“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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Thursday, 19 March 2015

Balancing Chemical Equations Worksheet

Balance these following chemical equations. show your working!

1.    ___Li2O  + ___H2O à ___LiOH
2.    ___CaC2  + ___H2O à ___C2H2  + ___Ca(OH)2
3.    ___Fe(OH)3 à ___Fe2O3  + ___H2O
4.    ___Pb(NO3)2  à ___PbO  + ___NO2  + ___O2
5.    ___BaO  + ___H2O à ___Ba(OH)2
6.    ___Ca  + ___AlCl3 à ___CaCl2  + ___Al
7.    ___NH3  + ___NO à ___N2  + ___H2O
8.    ___H3PO3 à ___H3PO4   + ___PH3
9.    ___Fe2O3   + ___C à ___CO  + ___Fe

10. ___FeS  + ___O2 à ___Fe2O3  + ___SO2

Saturday, 7 March 2015

Slides: Types of Chemical Reaction

click here to download the presentation slide

Types of Reaction Worksheet and Answer

Types of Chemical Reactions Worksheet

There are 5 major types of reactions simplified by the following equations:
  • Synthesis/Combination      A + B à AB
  • Decomposition                     AB à A + B
  • Combustion                          ? + O2 à ?
  • Single Replacement            X + AB à XB + A               or            Y + AB à AY + B
  • Double Replacement          XY + AB à XB + AY

Classify each of the following reactions:

1. Zn   +    Cl2  à ZnCl2                                 combination
2. 2 H2S +   3 O2 à   2 SO2  +    2 H2O         combustion
3. Cu + 2 AgNO3 à Cu(NO3)2 + 2 Ag          single replacement
4. Mg(OH)2 à MgO + H2O                           decomposition
5. CaCl2    +    Na2SO4 à CaSO4 + 2 NaCl   double replacement
6. CaO +    H2O à Ca(OH)2                                      combination  
7. Pb  + 4 HCl à PbCl4 + 2 H2                      single replacement
8. Li2O +   CO2 à LiCO3                               combination
9. SO2 +   H2O à H2SO3                               combination
10. MgCO3 à MgO + CO2                            decomposition
Predict the product and Classify each of the following reactions when only the reactants are given:

1. Mg  +  N2 à Mg3N2                                             combination
2. C2H6 +  O2 à CO2  +  H2O                                  combustion
3. Zn  + CuCl2  àZnCl2   +  Cu                               single replacement
4. Ca  + H2àCa(OH)2 + H2                                single replacement
5. AgNO3    +    NaI àAgI  + NaNO3                      double replacement
6. Fe(NO3)3    +    LiOH à Fe (OH)3 + LiNO3        double replacement
7. MgCO3 àMgO + CO2                                          decomposition
8. SO2 +    H2O àH2SO3                                          combination
9. HI àH2 + I2                                                          decomposition
10. H2SO4    +    LiOH à Li2SO4  +  H2O              double replacement
Convert these following into symbol equations
  1. Some grey magnesium ribbon was added to colourless dilute hydrochloric acid. The metal dissolves producing magnesium chloride and produces some hydrogen gas.

Mg(s)  +  HCl(aq)   à  MgCl2(aq)  +  H2(g)
  1. Some zinc metal is added to copper(11) sulphate solution. The zinc becomes coated with copper and colourless zinc sulphate solution is produced.

Zn(s)  +  CuSO4(aq)  à  ZnSO4(aq)  +  Cu(s)
  1. Some colourless hydrogen gas is mixed with colourless oxygen gas. The mixture is sparked and it explodes producing steam which condenses to liquid water.

H2(g)  +  O2(g)  à  H2O(l)
  1. Magnesium ribbon is burnt in carbon dioxide gas. It burns splattering as it goes. Black carbon is produced and some magnesium oxide solid.

Convert these word equations below into symbol symbol equations. Then classify the following reactions, represented by word equations, as synthesis/combination, decomposition , single replacement, double replacement, combustion
1)      sulphur + oxygen à  sulphur dioxide                                    ……………...

S  +  O2  à  SO2                               combination

2)      sodium + chlorine à  sodium chloride                                   ……………...

Na    +  Cl2   à   NaCl                      combination

3)      magnesium + oxygen à   magnesium oxide                          ……………...

Mg   +    O2    à    MgO                   combination/combustion

4)      magnesium + hydrochloric acid    ----------->  magnesium chloride + hydrogen ……………...

Mg    +   HCl    à   MgCl2    +   H2 single replacement

5)      calcium carbonate ----------->.calcium oxide + carbon dioxide                                   ……………...

CaCO3  à  CaO   +  CO2                decomposition

6)       mercury oxide      -------------->  mercury + oxygen                           ……………...

            Hg2O  à  Hg  + O2                           decomposition

7)      sodium nitrate à sodium nitrite + oxygen                 ……………...

NaNO3  à  NaNO2  +  O2               decomposition

8)      aluminium + iron III oxide  -------------->aluminium oxide + iron ……………...

            Al   +   Fe2O3   à  Al2O3   +  Fe     single replacement

9)      cobalt II chloride crystals --------------->.anhydrous cobalt chloride + water vapour                   
                                              HEAT                                                                 ……………...

CoCl2. n H2O  à   CoCl2   +   H2O           decompostion

10)  nitrogen + hydrogen ---------------> ammonia (hydrogen nitride) ……………...
                                  iron catalyst

            N2  +   H2   à  NH3                          combination

Friday, 6 March 2015

IGCSE Chemistry paper

Wednesday, 4 March 2015