11th Revision Chemistry Ch-1_Final ppt.pptx

1. Importance of Chemistry:
Chemistry plays a crucial role in science, medicine, technology, and industry. It is the study of matter, its properties, and the changes it undergoes during reactions.

2. Laws of Chemical Combinations:
Law of Conservation of Mass: Mass can neither be created nor destroyed in a chemical reaction.
Law of Definite Proportions: A chemical compound always contains the same elements in a fixed proportion by mass.
Law of Multiple Proportions: When two elements combine in different ways, the ratios of their masses form simple whole numbers.
Gay Lussac's Law of Gaseous Volumes: Gases combine in simple whole-number ratios by volume under the same conditions of temperature and pressure.
Avogadro's Law: Equal volumes of gases, under the same conditions of temperature and pressure, contain an equal number of molecules.
3. Atomic and Molecular Mass:
Atomic Mass: The average mass of an element's atoms compared to the 1/12th of the mass of a carbon-12 atom.
Molecular Mass: The sum of the atomic masses of all the atoms in a molecule.
4. Mole Concept:
A mole is the amount of substance containing the same number of entities (atoms, ions, or molecules) as there are in 12 grams of carbon-12. This number is Avogadro's Number (6.022 × 10²³).
It connects macroscopic quantities like mass to microscopic quantities like the number of particles.
5. Molar Mass:
The mass of one mole of a substance (in grams), equal to its molecular or atomic mass in atomic mass units (amu).

6. Percentage Composition:
The mass percentage of each element in a compound. It is calculated by:

Percentage
=
Mass of element in 1 mole of compound
Molar mass of compound
×
100
Percentage=
Molar mass of compound
Mass of element in 1 mole of compound
​
×100
7. Empirical and Molecular Formula:
Empirical Formula: The simplest whole-number ratio of atoms of each element in a compound.
Molecular Formula: The actual number of atoms of each element in a molecule, which can be a multiple of the empirical formula.
8. Stoichiometry:
Stoichiometric Calculations involve using the balanced chemical equation to calculate the masses or volumes of reactants and products in a chemical reaction.
Limiting Reagent: The reactant that is completely consumed in a reaction, thus limiting the amount of products formed.
9. Concentration Terms:
Molarity (M): Moles of solute per liter of solution.
Molality (m): Moles of solute per kilogram of solvent.
Normality (N): Gram equivalents of solute per liter of solution.
Mass Percentage, Volume Percentage, and Mole Fraction are other ways to express the concentration of solutions.

1. 11 th Revision Chemistry Chapter-1

2. Q-8 SA 1.2

3. Q-9 SA 1.3

4. Q-8 PPC 1.4

5. Q-10 SA 1.3

6. Q-8 PPC 1.3

7. Q-11 PPC 1.3

8. Q-13 PPC 1.3

9. Q-4 PPC 1.5

10. Q-8 SA 1.5

11. Q-6 PPC 1.5

12. Q-12 PPC 1.5

13. Q-9 SA 1.5

14. Calculate the mass of urea (NH 2 CONH 2 ) required in making 2.5 L of 0.25 molal aqueous solution. (Molar mass of urea= 60 gm/mol)

15. Q-4 PPC 1.6

16. Q-6 PPC 1.6

17. Q-7 PPC 1.6

18. Q-8 PPC 1.6

19. Q-11 PPC 1.6

20. Q-9 SA 1.6

21. Q-4 PPC 1.2

22. Q-8 PPC 1.2

23. Q-5 PPC 1.2

24. Q-9 PPC 1.2

25. Q-6 SA 1.3

26. Q-4 PPC 1.3

27. Q-4 SA 1.3

28. Q-12 PPC 1.3

29. Q-6 PPC 1.4

30. Q-5 PPC 1.4

31. Q-7 PPC 1.4

32. Q-11 PPC 1.4

33. Q-8 PPC 1.5

34. Q-7 SA 1.5