3. Metals and Non-metals Science class 10 exercise Additional Questions With Solutions
3. Metals and Non-metals Science class 10 exercise Additional Questions With Solutions ncert book solution in english-medium
NCERT Books Subjects for class 10th Hindi Medium
Chapter Review
Chapter Review:
- Metals, in their pure state, have a shining surface. This property is
called metallic lustre. - Some metals can be beaten into thin sheets. This
property is called malleability. - The ability of metals to be drawn into thin wires is called ductility.
- Gold is the most ductile metal a wire
of about 2 km length can be drawn from one gram of gold. - The metals that produce a sound on striking a hard surface
are said to be sonorous. - The best conductors of heat are silver and
copper. Lead and mercury are comparatively poor conductors of heat. - Full Form of PVC is polyvinylchloride.
- Gallium and caesium have very low melting points.
- Iodine is a non-metal but it is lustrous.
- Diamond, an allotrope of carbon, is
the hardest natural substance known and has a very high melting
and boiling point. - Graphite, another allotrope of carbon, is a conductor of electricity.
- Lithium, sodium, potassium are so soft that they can be cut with a knife. They have low densities and low melting points.
- Metals such as potassium and sodium react so vigorously that they catch fire if kept in the open.Therefore they are kept immersed in kerosene oil.
- Anodising is a process of forming a thick oxide layer of aluminium.
- Aqua regia is a freshly prepared mixture of concentrated hydrochloric acid and concentrated nitric acid in the ratio of 3:1.Aqua regia is a highly corrosive, fuming liquid.
- The metals at the top of the activity series (K, Na, Ca, Mg and Al) are so reactive that they are never found in nature as free elements.
- The metals in the middle of the activity series (Zn, Fe, Pb, etc.) are moderately reactive. They are found in the earth’s crust mainly as oxides, sulphides or carbonates.
- Ores mined from the earth are usually contaminated with large amounts of impurities such as soil, sand, etc., called gangue.
- Cinnabar (HgS) is an ore of mercury.
- The sulphide ores are converted into oxides by heating strongly in the presence of excess air. This process is known as roasting.
- The carbonate ores are changed into oxides by heating strongly in limited air. This process is known as calcination.
- Galvanisation is a method of protecting steel and iron from rusting
by coating them with a thin layer of zinc. - The rusting of iron can be prevented by painting, oiling, greasing,
galvanising, chrome plating, anodising or making alloys. - When iron is mixed with nickel and chromium, we get stainless steel, which is hard and does not rust.
- An alloy is a homogeneous mixture of two or more metals, or a metal and a non-metal.
- Pure gold, known as 24 carat gold, is very soft. It is, therefore, not suitable for making jewellery.
- The alloy of mercury is known as an amalgam.
- The extraction of metals from their ores and then refining them for use is known as metallurgy.
Text-book Questions
Text-book Questions with Solution:
NCERT Book Page 40
Q1: Give an example of a metal which
(i) is a liquid at room temperature.
(ii) can be easily cut with a knife.
(iii) is the best conductor of heat.
(iv) is a poor conductor of heat.
Answer:
(i) Metal that exists in liquid state at room temperature is Mercury.
(ii) Metals that can be easily cut with a knife are Sodium and Potassium
(iii) Metals that are the best conductor of heat are Silver and Gold
(iv) Metals that are poor conductors of heat are Mercury and lead.
Q2. Explain the meanings of malleable and ductile.
Answer:
Meliable: Some metals can be beaten into thin sheets by beating such substances are called malleable.
Ductile: Some substances can be drawn into thin wires such substances are called ductile.
Page No. 46
Q1. Why is sodium kept immersed in kerosene oil?
Answer: Sodium and potassium are highly reactive metals, they react with air and catch fire easily, so sodium is kept immersed in kerosene.
Q2. Write equation for the reactions of
(i) iron with steam
(ii) calcium and potassium with water
Answer:
(i) 3Fe(s)+ 4H2O(g)→ Fe3O4+4H2(g) |
(ii) Ca(s)+2H2O(I)→ Ca(OH)2 (aq)+H2(g) |
Q3. Samples of four metals A, B, C, and D were taken and added to the following solution one by one. The results obtained have been tabulated as follow:
Use the table above to answer the following questions about meals A,B,C and D.
(i) Which is the most relative metal?
(ii) What would you observe of B is added to a solution of copper (II) sulphate.
(iii) Arrange the metals A,B,C and D in the order of decreasing reactivity.
Answer: (i) Metal B is more reactive metal.
(ii) displacement reaction will take place.
(iii) Metal B > Metal A > Metal C > Metal D
Q4. Which gas is produced when dilute hydrochlroic acid is added to a reactive metal? Write the chemical reaction when iron reacts with dilute H2SO4.
Answer: Hydrogen gas is released.
Fe (s) + H2SO4 → FeSO4 (aq) + H2 (g)
Q5. What would you observe when zinc is added to a solution of Iron(II) sulphate? write the chemical reaction that takes place?
Answer: Zinc displaces iron from iron sulphate solution.
Zn + FeSO4 → ZnSO4 + Fe
Page no. 49
Q1. (i) Write the electric-dot structure for sodium, oxygen and magnesium.
(ii) Show the formation of Na2O and MgO by the transfer of electrons.
(iii) What are the ions present in these compound?
Q2. Why do ionic compound have high melting points?
Answer: The mutual ionic attraction is very strong in an ionic compound. It takes a lot of energy to break this powerful bond. Hence their melting point is high.
Page no. 53
Q1. Define the following terms.
(i) Mineral (ii) Ore (iii) Gangue
Answer: (i) Minerals are those substances in which metals are found in the form of their compounds.
(ii) Such minerals in which the extraction of metals is very easy and suitable are called ores.
(iii) Minerals are not found pure in nature, the impurities present in them are called gangue.
Q2. Name two metals which are found in nature in the free state.
Answer: Gold and Platinum.
Page no. 55
Q1.Metalic oxides of zinc, magnesium and copper were heated with the following metals.
Metal | zinc | magnesium | copper |
zinc oxides | |||
magnesium oxides | |||
copper oxides |
In which case will you find displacement reactions taking place?
Answer:
Metal | zinc | magnesium | copper |
zinc oxides | no | yes | no |
magnesium oxides | no | no | no |
copper oxides | yes | no |
Q2. In which metal do not corrode easily?
Answer: Gold, Platinum and Silver.
Q3. What are alloys?
Answer: A homogeneous mixture of two or more metals is called an alloy.
Exercise
Exercise
Q1. Which of the following pairs will give displacement reactions?
(a) NaCl solution and copper metal
(b) MgCl2 solution and aluminium metal
(c) FeSO4 solution and silver metal
(d) AgNO3 solution and copper metal.
Ans.1(d)Agno3 solution and copper metal.
Q2. Which of the following methods is suitable for preventing an iron frying pan from
rusting?
(a) Applying grease
(b) Applying paint
(c) Applying a coating of zinc
(d) All of the above.
Ans.2 Applying a coating of zinc.
Q3. An element reacts with oxygen to give a compound with a high melting point. This
compound is also soluble in water. The element is likely to be
(a) calcium
(b) carbon
(c) silicon
(d) iron.
Ans.3 Calcium
Q4. Food cans are coated with tin and not with zinc because
(a) zinc is costlier than tin.
(b) zinc has a higher melting point than tin.
(c) zinc is more reactive than tin.
(d) zinc is less reactive than tin.
Ans.4 food can is coated with tin not to Zinc because Zinc is more reactive than tin.
Q5. You are given a hammer, a battery, a bulb, wires and a switch.
(a) How could you use them to distinguish between samples of metals and
non-metals?
(b) Assess the usefulness of these tests in distinguishing between metals and
non-metals.
Ans.5 (a) We can beat the samples with hammer and the sample which will be beaten into thin sheets then it will be the metal and the sample which will not malleable is Non metal.Wecan use the battery,bulb,wires and switch to set up a circuit with both samples, the sample through which electricity would conduct will be metal,and which will not Non metal.
(b)These above tests are useful for distinguishing between Metal and non metal.These tests are based on the physical properties and not on chemical properties.
Q6. What are amphoteric oxides? Give two examples of amphoteric oxides.
Ans.6 Those oxides that act as both acidic as well as basic oxides. Such metal oxides react with both acid and base to produce salt and water are known as amphoteric oxides.
for example- Aluminium oxide, Zinc oxides etc.
Q7. Name two metals which will displace hydrogen from dilute acids, and two metals
which will not.
Ans.7 Metals that are more reactive than hydrogen (in reactivity series ) will displace hydrogen from dilute acids such as sodium and potassium.
Metal that are less reactive than hydrogen displace hydrogen from dilute acids.Such as- copper and silver.
Q8. In the electrolytic refining of a metal M, what would you take as the anode, the
cathode and the electrolyte?
Ans.8 In the electrolytic refining of metal M -
1. we would take impure metal M as anode.
2. We would take strip of pure metal M as cathode.
3. We would take solution of the salt solution of metal M as electrolyte.
Q9. Pratyush took sulphur powder on a spatula and heated it. He collected the gas
evolved by inverting a test tube over it, as shown in figure below.
(a) What will be the action of gas on
(i) dry litmus paper?
(ii) moist litmus paper?
(b) Write a balanced chemical equation for the reaction taking place.
Ans.9 (i) There will be no effect of evolved gas on dry litmus paper.
(ii) The evolved gas will turn the moist blue litmus to red because the gas produced is sulphur dioxide, because react with moisture to form sulphurous acid.
Q10. State two ways to prevent the rusting of iron.
Answer: There are two ways to protect iron from corrosion:
(i) By Isolation - In this method a thin layer of zinc is applied on iron and steel.
(ii) By painting - In this method, the iron object is painted so that its surface is not in direct contact with air and humidity.
Q11. What type of oxides are formed when non-metals combine with oxygen?
Answer: Non-metals combine with oxygen to form acidic oxides.
Q12. Give reasons
(a) Platinum, gold and silver are used to make jewellery.
(b) Sodium, potassium and lithium are stored under oil.
(c) Aluminium is a highly reactive metal, yet it is used to make utensils for cooking.
(d) Carbonate and sulphide ores are usually converted into oxides during the process of extraction.
Answer: (a) Platinum, gold and silver are lustrous metals and do not corrode, so they are used for making jewellery.
(b) Sodium, potassium and lithium easily catch fire due to their high reactivity when left open in air. Hence it is stored inside the oil.
(c) Aluminum utensils do not corrosive easily, so they are good conductors of heat.
(d) It is a much easier process to separate metals from their oxides, so carbonate and sulphide ores are converted into oxides in the extraction process.
Q13. You must have seen tarnished copper vessels being cleaned with lemon or tamarind juice. Explain why these sour substances are effective in cleaning the vessels.
Answer: A substance like lemon or tamarind contains acid, this acid is effective in cleaning the impure substance of copper, due to which the luster of copper utensils remains.
Q14. Differentiate between metal and non-metal on the basis of their chemical properties.
Answer: Chemical properties of metals:
(i) Metals form basic oxides.
(ii) Metals are reducing agents.
(iii) Metals displace hydrogen from water.
Chemical Properties of Nonmetals:
(i) Non-metals form acidic or neutral oxides.
(ii) Non-metals are oxidising.
(iii) Non-metals are not able to displace hydrogen from water.
Q15. A man went door to door posing as a goldsmith. He promised to bring back the
glitter of old and dull gold ornaments. An unsuspecting lady gave a set of gold
bangles to him which he dipped in a particular solution. The bangles sparkled
like new but their weight was reduced drastically. The lady was upset but after a
futile argument the man beat a hasty retreat. Can you play the detective to find
out the nature of the solution he had used?
Answer: The man used "Aqua Regia" solution to dissolve the woman's gold and the weight was reduced. It contains concentrated HCl and concentration HNO3 in a 3:1 ratio.
Q16. Give reasons why copper is used to make hot water tanks and not steel (an alloy
of iron).
Answer: Copper is a good conductor of heat and it does not react with hot water, on the contrary iron reacts with hot water.
Additional Questions With Solutions
Additional Questions With Solutions:
Q1: What is malleability?
Ans: Some metals can be beaten into thin sheets. This property is called malleability. Ex. – gold , Silver.
Q2: What is ductility?
Ans: The ability of metals to be drawn into thin wires is called ductility. Such a metal is called ductile metal. Ex. – gold and silver.
Q3: What is sonorous?
Ans: The metals that produce a sound on striking a hard surface are said to be sonorous.
Q4: Why are school bells made of metals?
Ans: The metals have a property of sonorous; they produce sound on striking a hard surface, so the school bells are made of metals.
Q6: Name two metals which melt to keep them on your palm.
Ans: Gallium and caesium.
Q7: Name a allotrope of carbon which is good conductor of electricity.
Ans: Graphite.
Q8: What do non metals produce when dissolve in water.
Ans: They produce acidic oxides.
Q11: What is anodising?
Ans: Anodising is a process of forming a thick oxide layer of aluminium.
Q13: What is done with the article to protect the further corrosion?
Ans: Anodising.
Q18: Name the metals which float in water.
Ans: Calcium and magnesium.
Q19: Why do Calcium and magnesium float in water?
Ans: Calcium and magnesium start floating because the bubbles of hydrogen gas formed stick to the surface of the metals.
Q20: Name two metals which do not react with hot or cold water but react with steam.
Ans: Aluminium and Iron.
Q21: What is the nature of metallic oxide?
Ans: Basic.
Q22: What is the nature of non-metallic oxide?
Ans: Acidic.
Additional Questions With Solutions
Additional Questions With Solutions:
Q1: Write three chemical properties of metals.
Ans: Three chemical properties of metals.
(i)All metals combine with oxygen to form metal oxides.
(ii)Metals react with water and produce a metal oxide and hydrogen gas.
(iii)Metals reacts with acids to give a salt and hydrogen gas.
Q2: Write three physical properties of metals.
Ans: Three physical properties of metals.
(i)Metals are ductile.
(ii)Metals are malleable.
(iii)Metals are sonorous.
Q3: What is amphoteric oxides? Give to examples.
Ans: The metals oxides which react with both acids as well as bases to produce salt and water and show both acids as well as basic behaviour are known as amphoteric oxides. Ex.- aluminium oxide and zinc oxide etc. q
Q4: Why are sodium or potassium kept immersed in kerosene oil?
Ans: Sodium or potassium reacts so vigorously that they catch fire if kept in open. Hence to protect them and to prevent to accidental fire they are kept immersed in kerosene oil.
Q5: The reaction metal X and Fe2 O3 is highly exothermic and is used to join railway.
(a) Identify metal X and name the reaction.
(b) Write the chemical equation of its reaction with fe2 O3.
Ans:
(a)X is (Al) Aluminium. Thermit Reaction.
(b)Fe2O3 (s) + 2Al(s) 2Fe(l) + Al2O3(s) + (Heat)
Q6: A metal X react with oxygen to form a blackish thin layer of oxide coat which protects itself to further corrosion.
(i)Identify the metal X.
(ii)What is called such a metal oxide.
(iii)What does it give to react with sodium hydroxide write its chemical equation.
Ans:
(i)Metal X is aluminium.
(ii)Aluminium oxide is called amphoteric oxides.
(iii)It react with sodium hydroxide gives sodium aluminate and water.
Q7: What is aqua regia?
Ans: Aqua regia is freshly prepared mixture of concentrated hydrochloric acid and concentrated nitric acid in the ratio of 3: 1. It is used to dissolve gold and clean the ornaments.
Q8: Why are the ornaments made of gold, silver and platinum?
Ans: Gold, silver and platinum have less reactivity so they don’t react with water and oxygen that cause corrosion. Hence the ornaments are made of gold, silver and platinum.
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Science Chapter List
1. Chemical Reactions and Equations
2. Acids, Bases and Salts
3. Metals and Non-metals
4. Carbon and its Compounds
5. Periodic Classification of Elements
6. Life Processes
7. Control and Coordination
8. How do Organisms Reproduce
9. Heredity and Evolution
10. Light-Reflection and Refraction
11. Human Eye and Colourful World
12. Electricity
13. Magnetic Effects of Electric Current
14. Sources of Energy
15. Our Environment
16. Management of Natural Resources
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