Science Made Easy: Mole & Avogadro’s number simplified

Now that a new batch of students has gone into class XI, it is time for them to pull up their socks – being in class XI brings them a little nearer to class XII Boards and the marks obtained have a crucial impact on the student’s prospects. A thorough understanding of every concept and topic becomes imperative including Science.

While only those students opt for this stream who are truly interested in the subject, it doesn’t take away the fact that certain topics can prove to be challenging to understand like Mole and Avogadro’s number. However, with a little effort and practice, it is possible to grasp these concepts, said Ramandeep Sandhu, a Chemistry teacher at Apeejay School, Mahavir Marg in Jalandhar.

“Mole and Avogadro’s number was taught to students of class IX. But it was deleted because it was found that students who were not interested in Science couldn’t grasp it. The topic is now taught to students of class XI. This topic is extremely important since we can’t separate Science from our daily lives,” Sandhu said and gave a real-life example where knowledge of both these concepts is handy.

When diving deep underwater, divers encounter increased pressure due to the weight of the water above them. This pressure affects the behaviour of gases, particularly the gases that divers breathe like oxygen and nitrogen. The behaviour of gases is governed by gas laws – Boyle’s Law, Charles’s Law, and the Ideal Gas Law. These laws describe the relationships between pressure, volume, temperature, and the number of gas particles. Avogadro’s number is a fundamental component of these gas laws.

“This can be relevant in deep-sea diving when considering the amount of gas that divers breathe. For instance, a diver might need a certain number of moles of oxygen to sustain their breathing at a particular depth and pressure,” Sandhu explained.

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In chemistry, a Mole is a unit used to measure the amount of a substance. It is similar to other counting units like a dozen (12 items) or a gross (144 items). A mole is an extremely large number: 6.022 x 10^23. This number is called Avogadro’s number

–Ramandeep Sandhu, a Chemistry teacher at Apeejay School, Mahavir Marg, Jalandhar

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The knowledge also comes into play if a person is suffering from carbon monoxide poisoning when a burning angithi is left in a closed room.

“In such a condition, the haemoglobin binds carbon monoxide to form carboxyhaemoglobin, cardiovascular disorders, and choking and the person can’t be given 21 per cent oxygen. The concentration of oxygen has to be in tune with the concentration of the carbon monoxide in the person’s body,” Sandhu shared and added that understanding these concepts has great importance in the field of medicine and the pharmaceutical sector.

What is Mole and Avogadro’s number?

In chemistry, a Mole is a unit used to measure the amount of a substance. It is similar to other counting units like a dozen (12 items) or a gross (144 items). A mole is an extremely large number: 6.022 x 10^23. This number is called Avogadro’s number.

Avogadro’s number represents the number of particles (atoms, molecules, ions, etc.) in one mole of a substance. For example, if you have one mole of water (H2O), you would have 6.022 x 10^23 water molecules. Similarly, one mole of carbon atoms would contain 6.022 x 10^23 carbon atoms.

How to calculate Mole

For example: Calculate the number of moles in 0.325 grams of barium hydroxide.

Mass of barium hydroxide = 0.325 gm

Molar mass of barium hydroxide = 171 gm

Moles = Mass of substance ÷ Mass of 1 mole

Put the values that you have

Moles = 0.325 ÷ 171 = 0.00190 mol

The concept of mole and Avogadro’s number may not be directly applicable to the day-to-day lives of the average person, but having a basic understanding of these concepts can be valuable. “Having a basic understanding of the mole concept can help individuals understand information related to drug dosages, medication instructions, and chemical reactions within the body,” Sandhu opined.

Areas where the grasp of Mole and Avogadro’s number is necessary

Concepts related to Mole and Avogadro’s number are relevant to understanding environmental issues like air pollution, climate change, and the behaviour of pollutants.

Understanding the principles of gas behaviour and gas laws can help individuals understand the importance of proper ventilation in confined spaces or the hazards associated with certain gases. It opens the door to further exploration of chemistry and related fields, enabling individuals to delve deeper into scientific topics if they choose to do so.