Metallurgy is actually an interesting of selina chemistry class 10 ch 7 metallurgy is that is found in Selina textbook for class 10 chemistry. STUDY IT provides step by step solutions for Selina Concise ICSE Solutions for Class 10 Chemistry Chapter 7 Metallurgy . You can download the Selina Concise Chemistry ICSE Solutions for Class 10 with Free PDF download option. Selina Publishers Concise Chemistry for Class 10 ICSE Solutions all questions are solved and explained by expert teachers as per ICSE board guidelines
This topic is very important and as many questions can be asked from this portion, we are providing free concise Chemistry class 10 ICSE Solutions for chapter 7 here.
Selina Class 10 ICSE Solutions
Selina Chemistry Class 10 ICSE Solutions
ICSE Solutions for Class 10 Chemistry Chapter 7 Metallurgy
1. (a)Name the three classes in which elements are classified. Which was the first metal used by man?
(b) Name the metal and non-metal present in abundance in the earth crust.
Solution:
- The three classes in which elements are classified are – metals, non-metals and metalloids. The first metal that was used by man was Copper. Copper was used to making weapons, utensils and for multiple purposes back in those days.
- The most abundant metal present in the earth’s crust is Aluminum and the most abundant non-metal present in the earth’s crust is Oxygen
2. Name the metal which is a constituent of:
(a) blood pigment (b) plant pigment
Solution:
The metal which is a constituent of the following are:
- Blood pigment – iron is a component of haemoglobin
- Plant pigment – magnesium is found in chlorophyll
3. State the position of the following in the periodic table:
(a) Alkali metals (b) Alkaline earth metals (c) Halogens (d) Aluminum
Solution:
The position of the following in the periodic table are:
- Alkali metals – they are the elements belonging to Group I in the periodic table. They are known to form strong alkalis with water. The outer electronic configuration of these elements is ns1
- Alkaline earth metals – they are the elements belonging to Group II. The electronic configuration of these metals is ns2
- Halogens – These are the elements belonging to Group 17th in the periodic table. The electronic configuration is ns2 np5
- Aluminum – It belongs to the Boron family, 13th group from the periodic table. The electronic configuration is ns2 np1
4. Why do gold ornaments look new even after several years of use?
Solution:
Ornaments made out of gold appear new even after several years of usage, this is because gold is less reactive. This can be observed in the reactivity series, it is placed low. Hence when gold comes in contact with atmospheric air or water it does not react, causes no corrosion. This is the reason why it looks new and does not lose its glitter and shine even after years.
5. Explain the following terms:
(a) ore (b) Gangue (c) Metallurgy
Solution:
- Ore – These are the minerals from which metals are extracted on a commercial scale at a relatively lower cost with least efforts.
- Gangue – Matrix or gangue is the earthly impurities that are typically mixed with minerals of metals. Example – sand, mud, soil limestone
- Metallurgy – it is a stream of science which deals with the extraction of metals in the purest form from their ores that are found occurring naturally in the environment
6. Which metal can be extracted from each one of the following ores:
(a) bauxite (b) calamine (c) haematite
Solution:
The metals that can be extracted from each one of the following ores are as follows:
(a) Bauxite – Aluminum
(b) Calamine – Zinc
(c) Haematite – Iron
7. Give the principles of:
(a) Hydrolytic method
(b) Froth floatation process
(c) Electromagnetic separation
Solution:
The principles of the following are:
Method |
Principle |
Hydrolytic method |
The main criterion is the difference in
densities of the ore and the gangue |
Froth floatation process |
The procedure depends on the preferential
wettability of the gangue particles by water and that ore with pine oil |
Electromagnetic separation |
Magnetic properties of the ore |
8. (a) Name the methods by which concentrated ore is converted to metallic oxide
(b) State three objectives achieved during the roasting of ores.
Solution:
- The methods by which concentrated ore is converted into metallic oxides are calcination and roasting. Concentrated ores are converted to their oxides as oxides are easier to reduce to metals. Hence these two methods are used to convert depending on the nature of the ores.
- Roasting is a process wherein concentrated ore is heated to a high temperature in the presence of air. The three objectives achieved during the roasting of ores are:
- Removal of moisture
- Oxidization of organic matter and its removal
- It makes the ore porous and hence causes the ores to get heated uniformly
9. Name
(a) the process involved in
(i) dressing of the ores (ii) refining of the ores
(b) two metallic oxides which cannot be reduced by carbon, carbon monoxide or hydrogen
Solution:
- The processes involved in:
- Dressing of ores are:
- Hydraulic washing
- Magnetic separation
- Froth floatation
- Chemical method/Leaching
- Refining of ores are:
- Distillation
- Liquation
- Electrorefining
- The two metallic oxides that cannot be reduced by carbon, carbon monoxide or hydrogen are oxides of sodium and potassium.
10. Why does iron or zinc does not occur freely in nature?
Solution:
Both iron and zinc are highly reactive hence do not occur in nature in their free states. Their sulphides, oxides and carbonates – their compounds of metals occur in nature.
11. What do you observe when hydrogen is passed over heated copper oxide?
Solution:
When hydrogen gas is made to pass over the heated copper oxide (CuO), the black coating present on the surface tends to change to a reddish-brown shade due to the occurrence of reverse reaction thereby producing copper. The latter reaction is known as redox reaction or oxidation-reduction reaction
12. (a)Name an ore of zinc
(b) Which process is applied to concentrate it?
(c) How is concentrated ore changed to oxide?
Solution:
- One ore of zinc is Zinc blende. Its chemical name is Zinc sulphide and its formula is ZnS.
- The process that is applied to concentrate it is froth floatation process
- The concentrated ore is changed to the oxide by heating Zinc blende (ZnS) in the presence of excess air. The reaction is as follows:
13. An ore on being heated in air forms sulphurous anhydride. Write the process used for the concentration of this ore.
Solution:
The process used for the concentration of this ore is froth floatation. This process depends on the preferential wettability of the gangue particles by water and that of the ore with pine oil.
13. (a) Define roasting. Name an ore on which roasting is done. Give a balanced equation.
(b) Define calcination. Give an example and equation for calcination.
Solution:
- Roasting is a process wherein concentrated ore is heated to a high temperature in the presence of air. An ore on which roasting is carried out is Zinc blende (ZnS) to yield its oxide, zinc oxide
- (ZnO). The equation is as follows:
- It is the process of heating concentrated ores such as carbonate or hydrated oxide in the absence of air to a high temperature. The temperature must be insufficient in melting the ore.
Example – Metal carbonates decompose to give metal oxides
ZnCO3 → ZnO + CO2
14. Choose the correct option:
(a) The metal other than aluminum, which has a strong affinity for oxygen is:
(A) Copper
(B) Magnesium
(C) Silver
(D) Gold
(b) A metallic oxide which cannot be reduced by normal reducing agents:
(A) Zinc oxide
(B) Magnesium oxide
(C) Copper (II) oxide
(D) Iron (III) oxide
Solution:
- The answer is (B) Magnesium
- The answer is (A) Zinc oxide
15. Fill in the blanks:
(a) Usually __________ (sulphide/carbonate) ores are subjected to _________ (calcination/roasting) which is done in the absence of air
(b) Zinc blende is converted to oxide by ___________ (roasting/calcination) process.
(c) Froth floatation process is generally used to concentrate __________ ores (sulphides/carbonate)
Solution:
- Carbonate, calcination
- Roasting
- Sulphides
16. State the position of aluminum in the periodic table.
Solution:
Aluminum, the most abundant metal in the earth’s crust has the following position in the periodic table – Period 3, Group IIIA (13)
17. (a) Give the chemical names and formulae of main ores of (i) aluminum (ii) iron (iii) zinc
(b) Which impurities are present in bauxite?
(c) What is red mud, how is it removed?
Solution:
- The chemical names and formulae
of the main ores are as given below:
Aluminum ores |
||
Name of the ore |
Chemical name |
Formula |
Cryolite |
Sodium aluminum oxide |
Na3AlF6 |
Bauxite |
Hydrated aluminum oxide |
Al3O3.2H2O |
Iron ores |
||
Name of the ore |
Chemical name |
Formula |
Brown heamatite |
Hydrated ferric oxide |
2Fe2O3.3H2O |
Red heamatite |
Anhydrous ferric oxide |
Fe2O3 |
Zinc ores |
||
Name of the ore |
Chemical name |
Formula |
Zinc blende |
Zinc sulphide |
ZnS |
Zincite |
Zinc oxide |
ZnO |
- Close to 60% of the bauxite ore
is composed of aluminum oxide. The other constituents are ferric oxide,
sand and titanium oxide
- Red mud is referred to as the
insoluble impurities. It consists of sand, ferric oxide etc that are
removed by filtration.
(a) bauxite
(b) sodium hydroxide
(c) Cryolite
(d) Graphite
Solution:
The significance of
each is as listed below:
Name of the
substance |
Significance in the
extraction of aluminum |
Bauxite |
Aluminum is extracted from the bauxite ore
as close to 60% of the bauxite ore is composed of aluminum oxide |
Sodium hydroxide |
In order to obtain pure aluminum oxide, the
ore from which aluminum is extracted is first treated with sodium hydroxide
solution |
Cryolite |
It is used to reduce the fusion temperature
and increases conductivity |
Graphite |
Used in the electrolytic reduction as thick
graphite rods |
19. What is an alloy? How do the properties of an alloy differ from its constituents?
Solution:
An alloy is a homogenous mixture of two or more metals or one of or more metals with a few non-metallic elements.
The properties of an alloy are different from its constituents. For instance, gold is too delicate and soft for usage without a slight percentage of copper. The bell metal is more sonorous than tin or copper. A small percentage of molybdenum enhances the wear resistance and toughness of steel. An alloy of cobalt, nickel and aluminum can lift a mass 60 times more than its own mass. The elements added in addition enhances the toughness, wear-resistance and other such characteristics.
20. What is amalgam? State its use with an example.
Solution:
An amalgam is a mixture or an alloy of mercury with many metals or an alloy of silver, gold, zinc, sodium also with some non-metals.
An example is an amalgam with a mixture of mercury and a silver tin alloy which is used as a dental amalgam.
Tags:- metallurgy class 10 icse pdf, icse class 10 chemistry chapter 8 solutions,selina class 10 chemistry book pdf, metallurgy class 10 icse questions, icse class 10 chemistry notes pdf, class 10 chemistry chapter 7 notes, candid icse chemistry class 10 solutions, icse class 10 chemistry chapter wise questions
To do so, students can check out free concise chemistry class 10 ICSE Solutions for chapter 7 – metallurgy provided here. With these solutions, they can clear all their doubts regarding the chapter and use it as an effective study tool to prepare well and fetch higher grades in the exams. These solutions are prepared by experts and are based on the latest board guidelines.
More Selina Concise Solutions Class 10
1 Comments
Online Casino Review, Software & Games | PayWatchTime.com
ReplyDeleteGet paid out on your first 안전한 온라인 카지노 deposit. Online casinos have a fantastic 오케이 카지노 selection of 샌즈 카지노 먹튀 games. Learn all about PayWatch Time and 메가 카지노 learn how to sign 샌즈 카지노 주소 up
Please Comment