Acids, Bases and Salts_ Part 1

Acids, Bases and Salts_ Part 1

By Utkersh Bora

​Physical Properties of Acids and Bases

​Some naturally occuring acids and their Chemical Formulas

​a. Vinegar (Acetic acid): CH₃COOH

b. Sour milk /Curd (Lactic acid): C₃H₆O₃

c. Orange/Lemon (Citric acid): C₆H₈O₇

d. Tamarind (Tartaric acid): C₄H₆O₆

e. Ant sting / Nettle sting (Formic Acid/Methanoic acid): HCOOH

f. Tomato (Oxalic acid): (COOH)₂

Multiple Choice

Which type of acid is found in Ant sting?

• Formic Acid

• Lactic Acid

• Oxalic Acid

• Acetic Acid

Multiple Choice

 Which one of the following is acidic?

• Lemon juice

• Tomato

• Milk

• All

Multiple Choice

What is the chemical formula for Acetic Acid/Ethanoic Acid/Vinegar?

• CH₃COOH

• C₂H₅OH

• HCOH

• (COOH)₂

Multiple Choice

Which of the following is the best remedy in case you get stung by a Bee?

• Wash it with soap and water.

• Apply Ice on it

• Apply Milk on it.

• Pour Turpentine Oil on it.

​Some Common Bases and their Uses?

​a. Sodium Flouride (NaF): Toothpaste, which we mostly use contains sodium fluoride which is slightly basic in nature.

b. Sodium Hydroxide (NaOH): In soaps, and cleaning products including detergents and washing powder

c. Sodium Bicarbonate (NaHCO₃): Sodium bicarbonate, commonly known as baking soda, is the regular item in our kitchens.

d. Magnesium Hydroxide (Mg(OH)₂): Magnesium hydroxide is the compounds that are used as anti-acid or for neutralizing the gastric acids.

Multiple Choice

What is the nature of the Toothpaste we use?

• Acidic

• Basic

• Neutral

• None of the above

Multiple Choice

Name a base that is generally used as an antacid and is called the milk of magnesia.

• NH₄(OH)

• CaO

• Ca(OH)₂

• Mg(OH)₂

Multiple Choice

What is the chemical Formula for Baking Soda?

• Na₂CO₃

• NaHCO₃

• CaSO₄.10H₂0

• None of the Above

​Indicators:

​An indicator is a ‘dye’ that shows a change in colour when brought in contact with acids and bases. This tells us whether the substance we are testing is an acid or base with respect to the change of colour.

​Some Common Indicators:

a. Litmus: Blue litmus paper turns red if the substance is acidic. Red litmus paper turns blue if the substance is basic or alkaline. Litmus turns red in acidic solutions and blue in basic solutions.

b. Methyl orange: Methyl orange shows red color in acidic medium and yellow color in basic medium.

c. Phenolphthalein: It turns colorless in acidic solutions and pink in basic solutions

d. Turmeric (Haldi) contains a yellow dye, which turns red in basic solutions and remains yellow in acidic or neutral soultions.

e. The red cabbage extract remains red in acidic solutions but turns green on adding to basic solutions.​

Multiple Choice

Turmeric is a natural indicator. On adding its paste to acid and base separately, which colours would be observed.

• Yellow in both acid and base

• Yellow in acid and red in base

• Pink in acid and yellow in base

• Red in acid and blue in base

Multiple Choice

Phenolphthalein is a synthetic indicator and its colours in acidic and basic solutions, respectively are:

• red and blue

• blue and red

• pink and colourless

• colourless and pink

​OLFACTORY INDICATORS:-

​The term ‘olfactory’ means ‘relating to the sense of smell’. So, olfactory indicators are those substances whose smell or odour changes in acidic or basic.

Onion, vanilla extract and Clove are common olfactory indicators.

Multiple Select

Which of the following can be used by a blind person to test whether a given product is acidic or basic?

• Vanilla Essence

• Turmeric

• Clove

• Red Cabbage Extract