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Chemical Equation

 
3.4  Chemical Equation
 
Chemical Equation
  • How to Write Chemical Equations Chemical equations can be written in the form of words or using chemical formulae.
  • The starting substances or reactants are written on the left-hand side of the equation while the new substances formed or products are written on the right-hand side of the equation.
  • The arrow '→’ means ‘produces’.
  • The physical state of each substance, whether solid(s), liquid(l), gas(g) or aqueous solution(aq) is usually indicated in a chemical equation.
 
Steps in Determining the Chemical Equation
  • The following diagram is the steps in determining the chemical equation:

The image is an infographic titled ‘Steps in Determining the Chemical Equation.’ It is divided into four steps, each represented by a box with a number and description: 1. Write the equation in the form of words. 2. Write the symbol in the substances. 3. Check the number of atoms for each element. 4. Write coefficient in front of the chemical formula to balance equation. The design uses blue and red colors for the boxes and has the Pandai logo on the top right.

  • Below shows an example of a chemical equation:
    • \(Mg(s) + 2HCl(aq) \rightarrow MgCl_2(aq) + H_2(g)\)

                 * Note: (s) solid state, (aq) aqueous state and (g) gas state.

  • From the chemical equation above, we know, solid magnesium and HCl are the reactants.
  • These two reactants react and become magnesium chloride.
  • For better understanding, pay attention to the coefficient for each reactant and product in the chemical equation.
    • One mole of magnesium reacts with 2 moles of hydrochloric acid to produce 1 mole of magnesium chloride and 1 mole of hydrogen gas. 
 

 

 

 

 

 

 

 

 

The views expressed in the notes here are those of the contributor and don’t necessarily represent the views of Pandai.

Chemical Equation

 
3.4  Chemical Equation
 
Chemical Equation
  • How to Write Chemical Equations Chemical equations can be written in the form of words or using chemical formulae.
  • The starting substances or reactants are written on the left-hand side of the equation while the new substances formed or products are written on the right-hand side of the equation.
  • The arrow '→’ means ‘produces’.
  • The physical state of each substance, whether solid(s), liquid(l), gas(g) or aqueous solution(aq) is usually indicated in a chemical equation.
 
Steps in Determining the Chemical Equation
  • The following diagram is the steps in determining the chemical equation:

The image is an infographic titled ‘Steps in Determining the Chemical Equation.’ It is divided into four steps, each represented by a box with a number and description: 1. Write the equation in the form of words. 2. Write the symbol in the substances. 3. Check the number of atoms for each element. 4. Write coefficient in front of the chemical formula to balance equation. The design uses blue and red colors for the boxes and has the Pandai logo on the top right.

  • Below shows an example of a chemical equation:
    • \(Mg(s) + 2HCl(aq) \rightarrow MgCl_2(aq) + H_2(g)\)

                 * Note: (s) solid state, (aq) aqueous state and (g) gas state.

  • From the chemical equation above, we know, solid magnesium and HCl are the reactants.
  • These two reactants react and become magnesium chloride.
  • For better understanding, pay attention to the coefficient for each reactant and product in the chemical equation.
    • One mole of magnesium reacts with 2 moles of hydrochloric acid to produce 1 mole of magnesium chloride and 1 mole of hydrogen gas. 
 

 

 

 

 

 

 

 

 

The views expressed in the notes here are those of the contributor and don’t necessarily represent the views of Pandai.
Chapter : Mole Concept, Chemical Formulae and Equations
Topic : Chemical Equation
Form 4 Chemistry
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