2. Noble metals such as gold and platinum do not corrode easily .
3. Alloys are homogenous mixture of elements where one elements is metal and another element can be metal or non-metal.
4. The metal that forms two types of its oxide and rust in moisture is iron. The formulas of its oxides are : FeO;Fe2O3
5. Iron and Aluminium
7. Metals have the tendency to loose electron i.e they are electron donor.Now Hydrogen is also electron donor,So That is why metals displace hydrogen from dilute Non-Metals have the tendency to gain electron i.e electron acceptor ,so they don't replace hydrogen
8. Metals are electropositive elements because they can form positive ions by losing electrons
11. Mercury is just below copper and lead is just above hydrogen
13. Copper, Silver , Tin-lead alloy are used in making fuse
16. Lead chloride
17. Na > Ca > Mg > Zn > Fe > Cu (least active).
18. Anode: The anode used for this process is made up impure.
Cathode: The cathode used for the electrolysis is pure copper sheets.
Electrolyte: Copper sulphate solution is used as an electrolyte in this process
19.Mercury is a metal which is liquid at room temperature. Iodine is a non-metal which is lustrous
Two Marks Questions
A copper plate was dipped in AgNO3 solution. After certain time silver from the solution was deposited on the copper plate. State the reason why it happened. Give the chemical equation of the reaction involved.
An element X on reacting with oxygen forms an oxide X2O. this oxide dissolves in water and turns blue litmus red.
Why are the two non- metals, carbon and hydrogen are important chemical reference points with regard to the method of metal extraction and reactivity towards acids.
What is the behavior of magnesium when I is heated and steam is passed over it? Represent the equation.
A zinc rod was kept in a glass container having CuSO4 solution. On examining, it was found that the blue color of the solution had faded. After few days when the zinc rod was taken out of the solution, a number of small holes were noticed in it. State the reason and give equation of chemical reaction involved.
What is gangue and what is concentration?
Lemon or tamarind juice are effective in cleaning tarnished copper vessels.
Four Marks Questions
What are the three major steps involved in extraction of a metal after its ore is mined?
Carbonates and sulphide ores are usually converted into oxide ores, why?
Name the types of reduction processes involved in metallurgy with an example for each.
An ore gave SO2on heating with oxygen. How will you concentrate this ore?
Write differences between metals and non-metals based on physical properties.
Show the formation of Na2O and MgO by the transfer of electrons
In metallurgy what do the terms gangue, flux, slag stand for? Give examples.
(i) In metallurgy, what does the term ‘Roasting’ stand for?
(ii) Name the by- product formed during roasting and give one of its uses.
How does roasting differ from calcinations? Give equations.
Why are aluminum containers used to transport nitric acid?
How is iron ore reduced in the blast furnace?
Why is Al obtained only by electrolytic reduction of Alumina (pure)?
Name the two ores of zinc commonly used.
Name two common alloys of zinc with their property and uses.
Five Marks Questions
In metallurgy, what do the term calcinations stand for? Give example? Answers
The carbonate ores are changed into oxides by heating strongly in limited air. This process is known as calcination
ZnCO3 (s) -> ZnO(s) + CO (g)
Name two metals that occur in a free state nature. What is the method of refining them? Answers
Gold and Platinum are two metals that occur in a free in state in nature. They only need to be cleaned by physical methods.
Draw a neat and well labelled diagram for electrolytic refining of copper Answers
Explain the formation of an ionic compound between a metal and a non- metal by transfer of electrons with Mg as the metal and chlorine as the non –metal to illustrate your answer. Give the reaction that occurs. Answers
Explain the chemical change that causes corrosion in iron. Answers
Iron reacts with Oxygen in the presence of water to form Iron Oxide [ferrous oxide(FeO),ferric oxide(Fe2O3)]
Iron + Oxygen (from environment) + Water (Humidity) -> Iron Oxide (Rust)
Fe + O2 + H2O —> FeO and Fe2O3
If an iron nail is left in a filled bottle of boiled water how long will it take to corrode? Question 7
What is the one of the most important use of zinc? Answers
To galvinize other metals to prevent rusting
(a) The following reactions are observed to occur:
(i) CuSO4 + Zn -> ZnSO4 + Cu
(ii) 3ZnSO4 + 2Al -> Al2(SO4)3 + 3Zn
(iii) 2AgNO3 + Cu -> Cu(NO3)2 + 2Ag
Arrange Cu, Zn, Al and Ag in decreasing order of their reactivity.
(b) Write one example each of decomposition reaction carried out with the help of:
(i) Electricity (ii) Sunlight. Answers
(a) Al > Zn > Cu > Ag
(i)The decomposition by electric current is called electrolytic decomposition process
H2O —> H2 + O2
(ii) The decomposition by light is called Photo decomposition process.
2AgCl -> 2Ag + Cl2
(a) Define reactivity series of metals. Arrange the metals gold, copper, iron, zinc and magnesium in their increasing order in reactivity.
(b) What will you observe when:
(i) Some Zinc pieces are put into copper sulphate solution?
(ii) Some silver pieces are put into green coloured ferrous sulphate solution? Answers
(a) Metals along with hydrogen (a non-metal) are arranged in order to their activity in a series, called the activity series or The Reactivity Series
Gold < Copper < Iron < magnesium
(b)Zinc will displace Cu to form ZnSO4
Zn + CuSO4 -> ZnSO4 + Cu
ii)no reaction will take place
Write the names and symbols of two most reactive metals. Explain by drawing electronic structure how any one of them reacts with a halogen. Explain any two physical properties of the compound formed. Answers
Sodium (Na) and Potassium (K).
Here is how Sodium reacts with Chlorine(Halogen)
a. Physical nature: Ionic compounds are solids and are somewhat hard because of the strong force of attraction between the positive
and negative ions. These compounds are generally brittle and break into pieces when pressure is applied
b. Melting and Boiling points:Ionic compounds have high melting and boiling points
In the formation of a compound XY2, atom X donates one electron to each Y atom. Show the electron dot structure of X, Y and the formation of XY2. What is the nature of bond in XY2? Write any three properties of compound XY2. The electronic configurations of the elements X and Y are as follows:
X - 2, 8, 2
Y - 2, 7 Answers
The compound formed is MgF2.
Bond formed is ionic
(1) It is a white crystalline salt.
(2) The compound is transparent over a wide range of wavelength.
(3) Are inert to organic chemicals and many acids.
(a) Write electron dot structure for chlorine (atomic no. 17) and calcium (atomic no. 20). Show the formation of calcium chloride by the transfer electrons.
(b) Identify the nature of the above compound and explain three physical properties of such compounds. Question 13
Explain why a salt which does not conduct electricity in the solid state but becomes a good conductor in molten state? Question 14
Give reasons why:
(i) Ionic compounds have high melting and boiling points.
(ii) Ionic compounds are soluble in water.
(iii)Ionic compounds are solid and somewhat hard.
(iv)Ionic compounds conduct electricity in molten state. Question 15
Metals towards the top of the activity series cannot be obtained from their compounds by reducing with carbon. Why? Question 16
The oxide X2O3 is unaffected by water. Name a method by which metal X can be obtained from its ore. Give one reason as to why have you chosen this method. Question 17
(i) How is copper obtained from its ore (sulphide ore)? Write balanced chemical equation.
(ii) How is impure copper purified by electrolytic refining? Draw a labeled diagram to illustrate it.
(iii)State your observation when a magnesium ribbon is burnt. Is magnesium oxidized or reduced? Question 18
An iron grill should be painted frequently. Question 19
(a) Define the terms 'alloy' and 'amalgam'. Name the alloy used for welding electric wires together. What are its constituents?
(b) Name the constituents of the following alloys:
(i) Brass (ii) Stainless steel (iii) Bronze Question 20
How can we prevent corrosion? Question 21
Metals like iron, silver and copper get corroded on exposure to air. Write the chemical name of the substance deposited on their surface respectively with its colour, in each case. Question 22
(a) Define the term alloy. Write two advantages of making alloys.
(b) A metal 'X' which is used in thermit process, when heated with oxygen gives an oxide 'Y' which is amphoteric in nature. Identify 'X' and 'Y'. Write down the reactions of oxide 'Y' with HCI and NaOH.
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