Basic chemistry for viii , ix and x

02/11/2022

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21/02/2020

1)Why carbon forms a large number of compounds ?
2)Name an another element belonging to the same group as carbon.
3)Why silicon does not form so many compounds as carbon although they belong to the same group?
4)what is catenation?
5)Differentiate between organic and inorganic compounds.
6)What are hydrocarbons ?Name their types with examples
7)How will you test for saturation and unsaturation of hydrocarbons?
8)What are alkanes alkenes and alkynes ?Give their general formulae
9)write the structural and electron dot formulae for first alkane alkene and alkyne.
10)what is homologous series and write 5 characteristics of this series.
11)give formula of one higher and one lower homologue of propane propene and propyne.
12)How methane is prepared in laboratory .write a balanced a chemical equation for this.
13)Why methane is called marsh gas ?
14)How methane is responsible for many deaths of workers during sewer line cleaning ?
15)Why all alkanes are excellent fuels but alkenes and alkynes are not ?
16)Why methane burns with non sooty flame while acetylene burns with sooty flame in a gas stove?
17)Write a balanced a chemical equation for combustion of methane in sufficient supply of oxygen.
18)Name a gas which is present in CNG,biogas and natural gas.
19)How is ethene prepared ?Give a balanced equation for that .
20)What are general names of ethene and ethyne?
21)What is meant by addition and substitution reactions .Explain with examples?
22)Which of the following can undergo addition and substitution and why?
Ethyne , propane , butene
23)what is the importance of addition reaction in 1)polymerisation 2 )in vegetable industry
24)What is meant by halogenation of alkane ?give an example to explain it with a series of compounds so formed?also write their IUPACE names
25)What is meant by oxy-acetylene flame and what is its importance in industries?
26)why pure oxygen but not air is used for production of oxy - acytelene flame?
27)write electron dot formula for carbon tetra chloride .
28)What are isomers and what is isomerisation ?give examples to explain one structural and one functional isomer
29)What is meant by functional groups?give examples.
30)write the IUPACE name and the structures of the functional groups present in the following compounds
1)propyl alcohol
2)acetone
3)vinegar
4)Ethene
5)formalin
31)Write reactions and the processes by which alcohols and acids are tested
32)What is meant by dehydration of ethanol give a reaction for it ?
33)What happens when ethanol is oxidised with alkaline potassium permanganate or acidified potassium dichromate?
34)give all possible isomers of a saturated carbon compound having 12 hydrogen atoms and also write their IUPACE Names.
35)Write the uses of vinegar and formalin.
36)Why normal acetic acid is called glatial acetic acid?
37)what happens when an organic acid reacts with an alcohol in presence of a few drops of conc. sulphuric acid ?
Give a balaced chemical equation for this?
Write the role of conc.sulphuric acid in this reaction.
What is the special name given to this reaction.
38)what are the uses of esters and organic acids ?
39)what is meant by saponification and how it is reverse to esterification?
Explain with suitable example
40)what are soaps and detergents ?
41)A detergent is called soapless soap explain
42)explain cleansing action of soap and why a detergent can not test for hard and soft water?
43)what are soap micelles ?how does it act on dirty clothes and clean it?
44) Differentiate between soaps and detergents
45)How some of the detergents are harmful to the environment ?

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11/08/2018

ACIDS, BASES AND SALTS
1. What are acids?
2. What are mineral acids and organic acids, give two examples of each?
3. What are the uses of mineral acids in industry?
4. What are strong and weak acids, give three examples of each?
5. Explain 4 properties of acids.
6. Why acids are not stored in metal containers? Containers/vessels made from which material is safe to store acids?
7. Write the chemical formula for:
(i) Acetic acid
(ii) Carbonic acid
(iii) Formic acid
8. In co2- type fire extinguishers which reaction takes place?
9. What are bases? What are hydroxides?
10. What are alkalies?
11. Give some examples of strong and weak bases?
12. Explain neutralization. How it is represented?
13. What are the indicators for testing acids and bases?
14. What are the uses of alkalies?
15. What is the other name for antacids?
16. What is salt? Write the chemical formula and uses of salts given below:
(i) Calcium sulphate
(ii) Copper sulphate
(iii) Sodium carbonate
(iiii) Calcium carbonate
(v) Magnesium sulphate
(vi) Ammonium sulphate
(vii) Ammonium nitrate
(viii) Ammonium chloride
(ix) Calcium phosphate
17.Write the chemical formula for:
(i) Sodium acetate
(ii) Potassium nitrate
(iii) Sodium carbonate
(iiii) Ammonium nitrate

18.What are acidic salts and basic salts? Give two examples.
19.What are hydrated salts? What do you understand by anhydrous and deliquescent salts?
20.What are the uses of sodium chloride?
21.How many types of salts are there?
22.State true (T) or false (f):
(I) Acid and alkali solution conduct heat.
(ii) Acids and alkalis are weak.
(iii) Salts are not soluble in water.
(iv) All bases are alkalies.
(v) Acids turn litmus in to blue.
(vi) Alkalies turn litmus into red.
23.How will you differentiate between neutral, acidic and basic salts? Give two examples of each type of salts.
24.What is missing in the following equation?
Fat +----------soap + glycerol
Zinc + hydrochloric acid --------+---------
Magnesium carbonate + hydrochloric acid ---------+--------+water
Calcium hydroxide + nitric acid----------+---------
Carbonic acid + sodium hydroxide---------+--------
Calcium carbonate + sulphuric acid-------+-------+carbon dioxide

25. (I) suggest one reason why baking powder is a mixture of sodium hydrogen carbonate and tartaric acid, and not just sodium hydrogen carbonate.
(ii) Complete the equation:

26.Write the chemical equation to represent the following reactions:
(i) Copper oxide reacts with hot dilute sulphuric acid to produce copper sulphate and water.
(ii) Sodium hydrogen carbonate is formed by the action of sodium hydroxide on carbonic acid.
(iii) Sodium phosphate is produced by the action of sodium hydroxide on phosphoric acid.
27.Distinguish between the two by giving examples:
(i) Acid and alkali
(ii) Organic acid and mineral acid
(iii) Base and alkali
28.What do you understand by the following words by giving examples?
(i) Soluble
(ii) Deliquescence
(iii) Normal salt
(iiii) Bases
(v) Hydrogen ions (H+)
(vi) Hydroxide ions (OH-)
29.Which of the following solids will turn neutral litmus solution blue?
(i) Magnesium oxide
(ii) Calcium oxide
(iii) Lead oxide


30.Name:
(i) Two substances that burn in air to give products, which dissolve in water to form alkaline solutions.
(ii) The substance formed when NO2 dissolves in water.
(iii) A substance, which, added to dilute hydrochloric acid, evolves hydrogen gas.
(iiii) The substance formed in solution dilute hydrochloric acid is added to copper oxide. Write its chemical formula.
(v) A substance that reacts with dilute nitric acid to form a nitrate and water as the only products.
(vi) Write one example each of the acids that form nitrates, sulphates, carbonates, chlorides and acetates.
(vii) Which of the following materials is almost neutral?
(i) Tap-water
(ii) Distilled water
(iiii) Rain water.
STRUCTURE OF MATTER
Q1.What is meant by chemical formula?
Q2.What is atomicity? Give examples for monoatomic, diatomic, triatomic.
Q3.Write the symbol for the elements given below:

a) Silver
b) Gold
c) Tin
d) Zinc
e) Magnesium
f) Manganese
Q4. Write the formula for the elements given below:
a) Bromine
b) Chlorine
c) Neon
d) Sulphur
Q5. Write the formula for the compounds given below:
a) Potassium permanganate
b) Ammonium chloride
c) Ammonia
d) Nitric acid
Q6. (a) Ne is the symbol of neon. What else does it represent?
(b) What does represent?
Q7. What do reactants and products mean?
Q8. Balance the equations:
a) H2 + Cl2 HCL
b) N2 + H2 NH3
c) Hg + O2 HgO
Q9. Two atoms of magnesium combine with one molecule of oxygen to form two molecules of magnesium oxide. Write the balanced equation.
Q10.one atom of carbon reacts with one molecule of oxygen to form one molecule of carbon dioxide.
Q11.Represent the reaction in the form of chemical equation:
a) One atom of Sulphur+ one molecule of oxygen one molecule of Sulphur dioxide.
b) One atom of zinc + two molecules of hydrochloric acid one molecule of zinc chloride + one molecule of hydrogen.

Q12.What is the difference between:
a) N2 and 2N
b) An atom of hydrogen and a molecule of hydrogen
c) A molecule of oxygen and a molecule of water
d) A molecule of sugar and a molecule of water
e) A molecule of magnesium oxide and a molecule of calcium oxide
Q13.Balance the following equations:
a) Zn + O2 ZnO
b) P + O2 P2O5
c) Al + O2 Al2O3
d) KNO3 KNO2 +O2
e) Na2O + H2O NaOH
Q14. What is the significance of Na?
Q15.What is the difference between balanced and unbalanced chemical equation? Explain with an example. What information is conveyed by balanced chemical equation?
Q16.Pure water is a compound, while seawater is a mixture. Explain why.
Q17.How many atoms of oxygen are obtained by decomposing a molecule of water?
Q18.Why can a gas be compressed easily?
Q19.Why is a solid substance hard and cannot be compressed?
Q20.Why does a solid melt on heating?
Q21.How many products are formed when electrolysis of water is done? Name.
Q22.How many kinds of atom are there in a molecule of copper carbonate?
Q23.What does the chemical formula of a compound represent?
Q24.Complete the following:
a) The particles of gases have _________ mobility.
b) Gases can be__________ easily.
c) A balanced chemical equation shows that atoms are______created ______destroyed in a chemical reaction.
d) A substance in which all the atoms are not alike, but all the molecules are alike.
e) Liquid particles _______over one another easily and take the ______of the container in which they are kept.
f) When a solid is heated, the forces of attraction between the particles are ________by the increased of the particles.
g) When a mixture of iron and Sulphur is strongly heated, it forms______.
h) A substance in which all atoms are alike is called an________.
i) In the gaseous state, particles can move in_________.
j) When wax is heated in a conical flask that has a long glass tube attached to it, the vapour of wax________.
Q25.What will happen if two cotton plugs, one soaked in liquid ammonia and another soaked in concentrated hydrochloric acid, are inserted simultaneously at the two ends of a half metre long glass tube?
Q26.For writing the chemical formula for compound, what are the factors we take into consideration?

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