Numericals of exercise, examples and self check exercises of stoichiometry-Chapter-1 Udrdu/English смотреть онлайн

Dear viewers,
In this video you will learn about the numericals of stoichiomtey which is chapter-1 of first year chemistry of federal board.
In this lecture i will discuss the following numericals
1.Example: 1.1
Methanol burns according to this equation
If 3.50 moles of methanol are burnt in oxygen , calculate
How many moles of oxygen are used?
How many moles of water are produce?
2.Self check exercise: 1.1
NH3 is an important raw material in the manufacturing of fertilizer. It is obtain by the combination of N2 and H2 as shown by following balance chemical equation
How many moles of the following are required to manufacture 5 moles of NH3
a. N2 b. H2
3.Example: 1.2
Iron can be produced from iron oxide (Haematite) Fe2O3 by reacting ore with CO. Carbon dioxide is produce in this reaction as a by product. What mass of Fe can be formed from 425g of iron ore?
4.Self Check Exercise: 1.2
The main engine of US space Shuttle are powered by liquid hydrogen and liquid oxygen. If 1.02x105 Kg of liquid hydrogen is carried on a particular launch, what mass of liquid oxygen is necessary for all the hydrogen to burnt the equation for the reaction is
5.Example 1.3
Calculate the number of molecules of O2 produced by thermal decomposition of 490grams of KClO3
6. 20 grams of H2SO4 on dissolving in water ionize completely, Calculate
a. Number of molecules of H2SO4
b.Number of H+ and SO4-2 ions
c. Mass of individual ions
7.Molar Volume
One mole of any gas at STP( T= 25C0 P= 1Atm) occupies a volume of 22.414dm3
a). How many moles of oxygen molecules are there in 50dm3 of oxygen at S.T.P?
(b). What volume does 0.8 moles of N2 gas occupy at STP?
8.Percentage composition
The relative mass of each element in a compound is expressed as a percentage composition
Steps
i.Determine the molecular/ Formula mass of compound
ii. Using the following formula find the percentage composition
% of each element (%Composition)= Mass of element in compound
Molecular/formula mass of compound
Example
What is the percentage composition of MgO
9.Limiting and Non Limiting Reactant
For Example 1.6
200 g of K2Cr2O7 were reactedwith 200g of Conc. H2SO4, Calculate \
a. Mass of atomic oxygen produce
b.Mass of reactant left unreacted
K2Cr2O7 + 4H2SO4 .................................. K2SO4 + Cr2(SO4)2 + 4H2O + 3O
Video link
https://www.youtube.com/watch?v=7tQK5SU5LS4&t=441s
10. Zinc and Sulphur react to form ZnS according to the following chemical reaction
If 6g of Zn and 4g of S are available for reaction, then determine the
Limiting reactant
Mass of ZnS produce

11. Self Check Exercise:
(2) Aluminum react with bromine to form aluminum bromide as shown by balance chemical reaction
2Al + 3 Br2 -------------------------------------- 2AlBr3
If 15.8g of Al and 55.6g of Bromine are available for reaction, then determine the
Limiting reactant
Mass of AlBr3 produce

12.Example 1.8
Suppose 1.87 moles of ammonium chloride were reacted with 1.35 moles of calcium hydroxide .How many grams of Ca(OH)2 are left unreacted in this reaction

13.Example 1.9
In an industry Cu metal was prepared by following reaction
1.27g CuSO4 when reacted with excess of Zn metal a yield of 0.392g of Cu metal is obtained
Calculate the percentage yield
% Yield = Actual yield x1oo
Theoretical yield

14. Example 1.10
In a reaction 2 moles of CH4 were reacted with an excess of Cl2 . As a result ,177g of CCl4 is obtained. What is
a. Theoratical yield b. Actual yield c. % yield

15. Self Check Exercise 1.5
1.The overall balance chemical equation for the production of ethanol (C2H5OH) from glucose is as follows

16. Self Check Exercise 1.5
2. Solid carbon dioxide (dry ice) may be used for refrigeration. Some of this CO2 is obtained as a by- product when hydrogen is produce from methane in the following reaction
CH4 + H2O ------------------------ H2 + CO2
What mass of CO2 should be obtained from 1250g of methane?
If the actual yield obtained is 3000g then what is percentage yield?
In a reaction 2 moles of CH4 were reacted with an excess of Cl2 . As a result ,177g of CCl4 is obtained. What is
a. Theoratical yield b. Actual yield c. % yield
17. iii. How many covalent bonds are present in 9g of water
18. . How many molecules of water are there in 12g of ice
19. The liquid CHBr3 has a density 2.89g/cm3 .What volume of this liquid should be measured to contain a total number of 4.8 x10 24 molecules of CHBr3
20. A small piece of pure Al metal having a volume of 2.5 cm3 is reacted with excess of HCL. What is the weight of H2 liberated? The density of Al is 2.7g/cm3
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