WATER + MILO MILO WATER
WATER + MILO MILO WATER
FLOUR + WATER + PRAWN PRAWN “CUCUR”
SYRAP + LIME + WATER LIME SYRAP
BREAD + JELLY + PEANUT BUTTER PEANUT BUTTER AND JELLY BREAD
CARBON + OXYGEN CARBON DIOXIDE
MAGNESIUM + SULPHURIC ACID MAGNESIUM SULPHATE + HYDROGEN
MAGNESIUM + HYDROCLORIC ACID MAGNESIUM OXIDE + HYDROGEN
HYDROGEN + NITROGEN AMMONIA
ALUMINIUM + IRON (III) OXIDE ALUMINIUM OXIDE + IRON
SILVER NITRATE + CALCIUM CHLORIDE SILVER CHLORIDE + CALCIUM NITRATE
CHEMICALEQUATION
• Chemical equation is a way of representing a chemical reaction.
• It shows the starting substances (reactants) and the new substances formed (products).
• There are 2 types of equations:– Word equation: uses words– Chemical equation: uses symbols and formulae
reactant + reactant product(s)
Can you identify which one is the reactant and which one is the product
1. water + milo milo water
reactant product
2. flour + water + prawn prawn “cucur”
reactant product
3. syrap + lime + water lime syrap
reactant product
4. CARBON + OXYGEN CARBON DIOXIDE
reactant product
5. MAGNESIUM + SULPHURIC ACID MAGNESIUM SULPHATE + HYDROGEN
reactant
product
Writing Chemical Equations
• Chemical equations have the same number of atoms of each element on both sides of the equation.– No atoms are created or destroyed during a
reaction. They are only rearranged.– Therefore, the number of atoms on both sides of
the equation must be equal.
• Sometimes, state symbols are shown. There are 4 state symbols:– solid (s)– liquid (l)– gas (g)– aqueous (aq)
dissolved
Reacting Hydrogen and Oxygen
Step 1: Write the word equation
Step 2: Write the chemical equation
hydrogen + oxygen water
H2 + O2 H2O
Reacting Hydrogen and Oxygen
Step 3: Check if the equation is balanced.H2 + O2 H2O
H – 2O – 2
H – 2O – 1
H2 + O2 2H2O
H – 2O – 2
H – 4O – 2
2H2 + O2 2H2O
H – 4O – 2
H – 4O – 2
Step 4 : Put in physical state or symbol that appropriate
2H2(g) + O2(g) 2H2O(l)
Test yourself
1. Potassium is burnt completely in the air to produce potassium oxide
2. Dehydration of hydrated copper (II) sulphate into copper sulphate and water
3. Zinc sulphate is decomposes when heated to produce zinc oxide and sulphur trioxide
Chemical Equation
Qualitative aspect Quantitative aspect
product reactant
Physical state
Number of mole
Can you interpret these chemical equation
1. 2KI (aq) + Br2(aq) I2(aq) + 2KBr (aq)
2. 3CuO (s) + 2Al (s) Al2O3(s) + 3Cu (s)
3. CaCO3 (s) ∆ CaO (s) + CO2 (g)
4. 2H2O2 (l) 2H2O (l) + O2(g)
5. 4CuO (s) + CH4 (g) 4Cu (s) + CO2(g) + 2H2O (l)
Can you do it????
25.0 gram of hydrated copper (II) sulphate crystal is heated according to the following formula CuSO4.5H2O CuSO4 + 5H2O
What is the mass of the dehydrated copper (II) sulphate that is formed??