9th Class Chemistry Chapter 1 Notes English Medium

Important Notes of 9th Class Chemistry Chapter 1 Notes English Medium  English Medium written by Professor M. Shahid Suib. These notes are very helpful in the preparation of 9th Class Chemistry Chapter 1 Notes English Medium for students of the 9th class Chemistry English Medium and these are according to the paper patterns of all Punjab boards.

Summary and Contents:
Topics which are discussed in the notes are given below:
  • Complete Exercise MCQs of Chapter No.1 Fundamentals of Chemistry
  • Complete Exercise Short Questions with Answers of Chapter No.1 Fundamentals of Chemistry
  • Define industrial chemistry and analytical chemistry
  • Define physical chemistry.
  • Define biochemistry and give its scope.
  • Define organic chemistry
  • Define inorganic chemistry.
  • What is a mixture? Give one example.
  • What is the difference between a homogeneous and heterogeneous mixture?
  • What is relative atomic mass? How is it related to gram? Write its unit.
  • Define the empirical formula with an example.
  • Define molecular formula with an example.
  • How molecular formula is derived from the empirical formula?
  • Define valency. Write the valency of Na.
  • Determine the molecular mass of Nitric acid (HNO3).
  • Define free radical.
  • Define ion with an example. How they are formed?
  • Define cations with an example. How they are formed?
  • Define anions with an example. How they are formed?
  • Define types of molecules and give examples of each. (Also A long Question).
  • Differentiate between atomic number and mass number.
  • Define atomic number and atomic mass.
  • Calculate the number of moles in 9 gram of carbon.
  • Calculate the number of moles in 6 grams of water.
  • What is meant by mole? Give an example. (Also a long question).
  • LONG QUESTIONS: Write down the differences between compound and mixture.
  •  How chemical formula is written? Explain its three steps.
  • Differentiate between molecule and Molecular ion.
  • Mole-Particle Calculations: In these calculations, we can calculate the number of moles of a substance from the given number of particles. (These particles are the atoms, molecules or formula units).
  • Number of moles = given number of particles / Avogadros number = given number of particles / 6.02 x 10^23
  • On rearranging above equation we get, Number of particles = number of moles x 6.02 x 10^23
  • Never calculate the number of particles from mass of the substance or vice versa.
  • For calculations of the number of atoms in molecular compounds and the number of ions in ionic compounds; first calculate the number of molecules or formula units and then calculate the number of atoms or ions.
  • THE MOLECULARITY OF THE PHYSICAL WORLD: The nature of the physical world as perceived through men's senses has been investigated in depth. The biggest lesson we learnt in 20th century is that Chemistry has become central science. It leads to the discovery of every chemical reaction in any living and non-living thing based on formation of "molecules". A reaction in the smallest living organism or in the most developed species like man, always takes place through the process of molecule formation. Hence it provides basis of "molecularity" of the physical world.
  • CORPUSCULAR NATURE OF MATTER: In 1924 de Broglie put forward the theory of dual nature of matter i.e. matter has both the properties of particles as well as waves. He explained the background of two ideas. He advocated that these two systems could not remain detached from each other. By mathematical evidences, he proved that every moving object is attached with waves and every wave has corpuscular nature as well. It formulated a basis to understand corpuscular nature of matter.
  • THE WORKS OF DIFFERENT SCIENTISTS AT THE SAME TIME HANDICAP OR PROMOTE THE GROWTH OF SCIENCE: Over the course of human history, people have developed many interconnected and validated ideas about the physical, biological, psychological and social worlds. Those ideas have enabled successive generations to achieve an increasingly comprehensive and reliable understanding of the human species and its environment. The means used to develop these ideas are particular ways of observing, thinking, experimenting and validating. These ways represent a fundamental aspect of the nature of science and reflect how science tends to differ from other modes of knowing.

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