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Thursday, September 28, 2023

X Science Guess Paper Carbon and its compounds

Guess Paper  Class – X Subject - Science Carbon and its compounds

Section A – one mark each
1..Alcohols can be produced by the hydration of.

2. Write the name of C60 molecule.

3. The property of carbon to form a long chain in compounds is called ……………

4   Which of the following compounds have triple bond     C2H4, C3H4 and C3H6

5.    The general formula CnH2n for cyclo alkanes is the same as that of ………….

6. Write structure formula of 2- methyl propane.

7. The IUPAC name of acetylene is …………………

8. Name the functional groups present in the following compounds
9.    ------and  ------are molecular formula of ethanol and propane.

10.  The IUPAC name of CH3CHO is ---------------

Section B – 2 marks each

11. Write the chemical equation of the reaction which takes place during burning of ethanol in air.

12. The molecular formula present in ester C3H7COOC2H5. Write the molecular formula of the alcohol and the acid from which it might be prepared.

13. A mixture of ethyne and oxygen is used for welding. Can you justify why a mixture of ethyne and air is not-used?

14. Write the reaction which is used as a test for ethanol and dehydration of ethanol.

15. What is reaction with ethanoic acid with ethanol?

                                             Section C – 3 marks each 

16.Write any three physical and chemical properties of ethanoic acid.

17. Write any three tests of carboxylic acids.

18. How many structural isomers are possible for pentane? Draw the structural formulae of all the possible isomers of pentane.

19. What are enzymes? Name the enzymes required for the fermentation of sugar cane to ethanol?

20. The formula of an ester is C3H7COOC2H5 write the formulae of the acid and alcohol from which the ester is prepared. 

Posts Related to Chapter 10th Carbon and its Compounds        View/Study

MCQs on Metallurgy class 10 chapter Metals and Non metals

Here are multiple-choice questions (MCQs) related to metallurgy Class 10:

1. What is the primary purpose of metallurgy?
   a) To study the properties of metals
   b) To extract and process metals from ores
   c) To create alloys from pure metals
   d) To manufacture metal products

2. Which of the following is NOT a step in metallurgy?
   a) Ore extraction
   b) Refining
   c) Alloying
   d) Fermentation

3. What is the first step in the extraction of metals from ores?
   a) Concentration
   b) Roasting
   c) Smelting
   d) Crushing and grinding

4. Which of the following is a common reducing agent used in smelting?
   a) Oxygen
   b) Carbon dioxide
   c) Carbon (coke)
   d) Hydrogen

5. What is the purpose of roasting in metallurgy?
   a) To remove volatile impurities
   b) To alloy metals
   c) To purify the metal
   d) To shape the metal

6. Which process is used to remove impurities from a metal after smelting?
   a) Casting
   b) Forging
   c) Refining
   d) Quenching

7. What is the result of combining iron with carbon in metallurgy?
   a) Aluminum
   b) Copper
   c) Steel
   d) Gold

8. Which step in metallurgy involves subjecting the metal to high temperatures to modify its properties?
   a) Refining
   b) Heat treatment
   c) Concentration
   d) Alloying

9. What is the purpose of quality control in metallurgy?
   a) To extract metals from ores
   b) To refine metals
   c) To ensure the final product meets standards
   d) To create alloys

10. In metallurgy, what is the final step after shaping and forming the metal?
    a) Refining
    b) Heat treatment
    c) Application
    d) Roasting

1. b) To extract and process metals from ores
2. d) Fermentation
3. d) Crushing and grinding
4. c) Carbon (coke)
5. a) To remove volatile impurities
6. c) Refining
7. c) Steel
8. b) Heat treatment
9. c) To ensure the final product meets standards
10. c) Application

Here are some additional multiple-choice questions (MCQs) related to metallurgy:

11. Which natural resources are the primary source of metallic ores in metallurgy?
    a) Fossil fuels
    b) Water bodies
    c) Earth's crust
    d) Atmosphere

12. What is the process called when metals react with oxygen to form metal oxides?
    a) Reduction
    b) Oxidation
    c) Refining
    d) Alloying

13. What is the term for the ability of metals to be drawn into wires?
    a) Malleability
    b) Ductility
    c) Conductivity
    d) Sonorousness

14. Which of the following is NOT a common non-ferrous metal?
    a) Copper
    b) Iron
    c) Aluminum
    d) Lead

15. What type of alloy is created when two or more metals are mixed together?
    a) Homogeneous alloy
    b) Composite alloy
    c) Heterogeneous alloy
    d) Impure alloy

16. Which metal is commonly used for electrical wiring due to its excellent conductivity?
    a) Aluminum
    b) Copper
    c) Iron
    d) Zinc

17. What is the process called when metals are heated and slowly cooled to relieve internal stresses and increase toughness?
    a) Casting
    b) Annealing
    c) Forging
    d) Smelting

18. Which property of metals makes them suitable for applications in musical instruments?
    a) Conductivity
    b) Sonorousness
    c) Ductility
    d) Malleability

19. Which metal is commonly used in aircraft construction due to its lightweight and corrosion-resistant properties?
    a) Iron
    b) Lead
    c) Aluminum
    d) Gold

20. In metallurgy, what is the term for the process of removing impurities by using a chemical reaction with a flux?
    a) Smelting
    b) Refining
    c) Quenching
    d) Alloying

11. c) Earth's crust
12. b) Oxidation
13. b) Ductility
14. b) Iron
15. c) Heterogeneous alloy
16. b) Copper
17. b) Annealing
18. b) Sonorousness
19. c) Aluminum
20. b) Refining

Thursday, December 5, 2019

METALS AND NON METALS Notes for class 8

1) Occurrence of metals and non metals :-
Out of the 92 naturally occuringelements 70 are metals and about 22 are nonmetals. 

Some elements show properties of both metals and non metals. They are called metalloids.
•Only some metals like gold, silver, platinum etc are found in the free state. Most metals are found in the combined states as oxides, sulphides, carbonates, silicates etc.
Some non metals are found in the free state like helium, neon, argon etc. and some are found in free and combined states like sulphur, phosphorus etc.
2) Metallurgy :-
•Metallurgy:-is science of extraction of metals from their ores and their purification.
•Minerals:-are naturally occuringsubstances containing one or more elements or their compounds.
•Ore:-is a mineral from which one or more metals can be extracted profitably.
•Metallurgical processes:-consists of three main steps. They are :-i) Concentration of the ore ii) Reduction iii) Refining
•Concentration of the ore:-is the removal of impurities from the ore.
•Reduction:-the process of obtaining the metal from its compound.
Refining:-is the process of purification of the impure metals to obtain the pure metal.
3) Physical properties of metals and non metals:-
•Metals are solids (except mercury).
•Metals are hard (except sodium, potassium etc.
•Metals have metallic lustre.
•Metals have high melting points and bolilingpoints.
•Metals are malleable ( can be made into thin sheets).
•Metals are ductile (can be made into thin wires).
•Metals are good conductors of heat and electricity.
•Metals are sonorus(produces sound).

•Non metals
•Non metals may be solids, liquids or gases.
•Non metals which are solids are brittle (diamond is the hardest).
•Non metals do not have lustresome have a dull luster.
•Non metals have low melting points.
•Non metals are not malleable.
•Non metals are not ductile.
•Non metals are bad conductors of heat and electricity (except graphite).
Non metals are not sonorous
4) Chemical properties of metals and non metals:-
a) Reaction with oxygen:-
Metals react with oxygen to form metallic oxides. These oxides are  basic oxides because they react with water to form bases. Eg. Magnesium burns in air to form magnesium oxide. Magnesium  reacts with water to form magnesium hydroxide.
2 Mg + O2--à2 MgO
MgO+ H2O-à  Mg(OH)2
Non metals react with oxygen to form non metallic oxides. These  oxides are acidic oxides because they react with water to form  acids.
Eg. Sulphurburns in air to form sulphurdioxide. Sulphurdioxide  reacts with water to form  sulphurousacid.
S + O2->SO2
SO2+ H2O---> H2SO3
b) Reaction with water:-
Metals react with water to form metal hydroxides and hydrogen.
Eg. Sodium reacts with water to form sodium hydroxide and  hydrogen.
2 Na + 2 H2O--> 2 Na OH + H2
Magnesium reacts with water to form magnesium hydroxide and hydrogen.
Mg + H2O ---> Mg(OH)2+ H2
Non metals do not react with water.
Metals react with acids to form metallic salts and hydrogen.
 Eg. Zinc reacts with dilute hydrochloric acid to form zinc chloride  and hydrogen.
Zn + 2 HCl -----> ZnCl2+ H2
Most non metals do not react with acids.
Some non metals like sulphur reacts with concentrated nitric acid to forn sulphur dioxide, nitrogen dioxide and water.
S + 4HNO3 ------> SO2+ 4 NO2+2 H2O
d) Metals replace metals:-
A more reactive metal replaces a less reactive metal from its salt  solution.
Eg. Magnesium replaces copper from copper sulphate solution to form magnesium sulphate and copper.
Mg + CuSO4---> MgSO4+ Cu
Zinc replaces copper from copper sulphate solution to for zinc sulphate and copper.
Zn + CuSO4-----> ZnSO4 + Cu
Iron replaces copper from copper sulphate solution to form iron sulphate and copper
Fe + CuSO4-----> FeSO4+ Cu
Based on the reactivity of metals, they can be arranged in the decreasing order of their activity.
5) Activity series of metals :-
The arranging of metals in the decreasing order of their reactivity is called activity series of metals.
In decreasindg order
Aluminium Decreasing
Zinc order of
Iron reactivity
6) Noble metals :-
Metals like gold, silver, platinum etc. retain their lustre because they do not react with air, water or acids. So they are called noble metals.
Gold dissolves in aqua regia. Aqua regia is a mixture of concentrated nitric acid and concentrated hydrochloric acid in the ratio 1:3.

Pure is 24 carat gold. It is very soft and cannot be used for making ornaments. So it is mixed with some silver or copper to make it hard.

7) Uses of metals :-
Iron :-is used for making pins, nails, nuts, bolts, tools,
machines, construction of buildings, bridges etc.

Aluminium :-is used for making utensils, wires, furniture,  parts of aircrafts, vehicles, machines, for packing food and medicines etc.
Copper :-is used for making wires, vessels, electric  gadgets etc.
Gold :-is used for making jewellery, coins medals etc
Silver :-is used for making jewellery. Coins, medals etc.
Platinum :-is used for making jewellery, electric gadgets, plugs in vehicles etc.
Sodium :-compounds are used as common salt,  chemicals etc.
Calcium :-compounds are used for making cement, glass etc.
8) Uses of non metals:-
Sulphur:-is used for making sulphuric acid, salts of  metals etc.
Oxygen:-is used for respiration by living things, burning  of fuels etc.
Nitrogen:-is used for making ammonia which is used for  making fertilizers.
Hydrogen:-is used for making ammonia which is used for making fertilizers, as fuel in rockets, for welding etc.
Chlorine:-is used to kill germs in water.
Iodine:-is used as tincture iodine which is an antiseptic
10) Corrosion:-
The surface of some metals gets corroded when exposed  to moist air for a long time. This is called corrosion.

Prevention of corrosion of metals:-

The corrosion of metals can be prevented by:-
i) Applying oil or grease.
ii) Applying paint
iii) Galvanisation ( coating of metals with non corrosive metals like zinc)
iv) Electroplating ( coating of metals with non corrosive metals like chromium tin by passing
v) Alloying ( Eg. When iron is alloyed with chromium and nickel, it forms stainless steel which is resistant to corrosion) 
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