Chemical Dynamics: Reactions in our daily substances

We use a large number of substances in our daily life such as lemon, curd, sugar, salt, tamarind etc. Some of these substances taste sour, some taste bitter, some taste sweet and some taste salty. Some of these substances change. Thus, A chemical reaction is described by a chemical equation, an expression that gives the identities and quantities of the substances involved in a reaction, emphasizing the significance of Chemical Dynamics in understanding these transformations.

Chemical Dynamics of Acids: Sour Side of Nature

• Meaning: Dynamics of Acidic Nature: The word acid comes from the ‘Latin’ word acere – means sour. 
  • Examples: Curd, lemon juice, orange juice and vinegar taste sour because they contain acids. 
  • Nature: The chemical nature of such substances is acidic. 

Bases: Bitter Essence and Soapy Touch in Chemical Dynamics 

• Meaning: Substances which are bitter in taste and feel soapy on touching are known as bases. 
• Example: Baking Soda.
• Nature: The nature of such substances is said to be basic.

Indicators  in Chemical Dynamics:

• Meaning: Indicators for Acid-Base Reactions: Substances used to test whether a substance is acidic or basic are known as indicators. 
• Observed Changes: The indicators change their colour when added to a solution containing an acidic or a basic substance.
  • Indicators can be both natural and synthetic.

How do Natural Indicators such as Litmus, Turmeric and China Rose reflect Chemical Dynamics in Acid-Base Reactions?

• Turmeric, litmus, china rose petals (Gudhal), etc., are some of the naturally occurring indicators.

Litmus: Nature and Significance of a Natural Dye

• The most commonly used natural indicator is litmus extracted from lichens. 
• Colour: It has a mauve (purple) colour in distilled water. 
• Observed Changes: When added to an acidic solution, it turns red and when added to a basic solution, it turns blue. 
• Presence: It is available in the form of a solution, or in the form of strips of paper, known as litmus paper (red and blue litmus paper).
• Neutral Solution: The solutions which do not change the colour of either red or blue litmus are known as neutral solutions. 
  • These substances are neither acidic nor basic.

Turmeric: Red Stain and the Basic Soap Solution

• Turmeric stain on white shirt turns to red when it is washed with soap. 
• It is because the soap solution is basic.

China Rose (Gudhal): Acidity in Pink and Alkalinity in Green

• China rose (Gudhal) indicator turns acidic solutions to dark pink (magenta) and basic solutions to green.

How do Synthetic indicators provide insights into the Chemical Dynamics of Acids and Bases?

• Synthetic indicators such as methyl orange and phenolphthalein are used to test for acids and bases.
• When the solution is basic, phenolphthalein gives a pink colour and when the solution is acidic, it remains colourless.

Olfactory indicators and their Aromatic responses to Acidic and Basic Environments:

• There are some substances whose odour changes in acidic or basic media. 
• These are called olfactory indicators.