Question
What is a chemical equation. How is it represented. Differentiate between a 'word equation' and a 'molecular equation' with a suitable example.
✓
Answer
“Chemical equation is a short form $–$ representing the result of a chemical change.”
OR
“Is the representation of a chemical change.”
Word equation tells which substances react $($take part$)$ in chemical reaction and which substances are produced where as molecular equation symbols and molecular formulas are used for both reactants and products.
Example :
When zinc reacts with dilute sulphuric acid, both being reactants, products produced are zinc sulphate and hydrogen gas, which are shown as below :
Word equation :
Zinc $+$ Sulphuric acid $\rightarrow$ Zinc sulphate $+$ Hydrogen
Molecular equation :
$\underset{\text { Zinc }}{ Zn }+\underset{\text { [Sulphuric acid] }}{ H _2 SO _4 \text { (dil.) }} \longrightarrow \underset{\text { [Zinc sulphate] }}{ ZnSO _4}+\underset{\text { [Hydrogen] }}{ H _2[ g ]}$
OR
“Is the representation of a chemical change.”
Word equation tells which substances react $($take part$)$ in chemical reaction and which substances are produced where as molecular equation symbols and molecular formulas are used for both reactants and products.
Example :
When zinc reacts with dilute sulphuric acid, both being reactants, products produced are zinc sulphate and hydrogen gas, which are shown as below :
Word equation :
Zinc $+$ Sulphuric acid $\rightarrow$ Zinc sulphate $+$ Hydrogen
Molecular equation :
$\underset{\text { Zinc }}{ Zn }+\underset{\text { [Sulphuric acid] }}{ H _2 SO _4 \text { (dil.) }} \longrightarrow \underset{\text { [Zinc sulphate] }}{ ZnSO _4}+\underset{\text { [Hydrogen] }}{ H _2[ g ]}$
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