Ncert Science Class 10 Solutions Chapter 3 Metals and Non-metals
Welcome to NCTB Solutions. Here with this post we are going to help 10th class students for the Solutions of NCERT Class 10 Science Book Chapter 3, Metals and Non-metals. Here students can easily find step by step solutions of all the questions in Metals and Non-metals. Also our Expert Science Teacher’s solved all the problems with easily understandable language with proper guidance so that all the students can understand easily. Here in this post students will get chapter 3 solutions. Here all Question Answer are based on NCERT latest syllabus.
Metals and Non-metals Exercise question Solutions :
(1) Which of the following pairs will give displacement reactions
Answer :
AgNO3 solution and copper metal gives displacement reaction.
AgNO3 + Cu → CuNO3 + Ag
Silver nitrate copper copper nitrate silver
Balanced Reaction
2AgNO3 + Cu → Cu(NO3)2 + 2Ag
(2) Which of the following methods is suitable for preventing an iron frying pan from rusting?
Answer :
The correct option is – (c)
Applying a coating of zinc.
Grease and paint get removed when it gets hot and also we cannot apply it on food equipment.
(4) 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
Answer :
The correct option is – (a)
All element reacts with oxygen but only calcium dioxide is soluble in water. Hence, calcium is the likely element.
(4) Food cans are coated with tin and not with zinc because
Answer :
The correct option is – (c)
Zinc is more reactive than tin and food items like drinks can react with zinc.
(5) You are given a hammer, a battery, a bulb, wires and a switch
Answer :
(a) Firstly, by hitting with hammer, if it breaks it is non metal and if it did not break it is metal, it will change shape because of malleability (property of metal).
Secondly, by making apparatus by connecting metal to two terminals of battery with metal through switch. If it passes current it is metal and vice versa.
(b) We can check conductivity and malleability of metal for sure.
(6) What are amphoteric oxides? Give two examples of amphoteric oxides.
Answer :
Metal oxide which reacts with both acid as well as base to form salt and water is called as amphoteric oxides.
Aluminum oxide and zinc oxide show both acidic and basic behavior.
(7) Name two metals which will displace hydrogen from dilute acids, and two metals which will not.
Answer :
Manganese and magnesium reacts with very dilute acids to evolve hydrogen gas. Silver and gold mostly will not react with dilute acids.
(8) In the electrolytic refining of a metal M, what would you take as the anode, the cathode and the electrolyte?
Answer :
The impure metal M is Made anode and the pure metal M is made cathode. The solution is metal M salt used as electrolyte.
(9) Pratyush took sulphur powder on aspatula and heated it. He collected the gas evolved by inverting a test tube over it, as shown in figure below
Answer :
(a) When Sulphur powder is heated in open air, it reacts with oxygen and forms sulphur dioxide.
(i) Oxide are acidic in nature. Acid shows acidic properties when mixed with water or moisture is available.so dry litmus will not work.
(ii) Wet blue litmus will turn in red, but wet red litmus will not turn blue.
(b) S + O2→ SO2
Sulphur oxygen sulphur oxide
SO2+ H2O→H2SO3
Sulphur oxide water hydrogen sulphide.
(10) State two ways to prevent the rusting of iron
Answer :
Rusting of Iron can be prevented by resisting the contact with water or air. This can be done by applying coating of other less active metal coating like galvanized iron, or by applying paints also by applying lubricants on surface of iron.
(11) What type of oxides are formed when non-metals combine with oxygen.
Answer :
When non metals come in contact or combined with oxygen they forms mostly acidic and neutral oxides. Carbon dioxide is acidic whereas carbon monoxide is neutral.
(12) Give reasons
Answer :
(a) Platinum, gold and silver are used to make jewellery
- Reason : Platinum, gold and silver are less reactive elements ,so it does not reacts with other elements present in atmosphere and does not get corroded. Also they are more ductile, malleable and non-corrosive. Hence used for jewellery.
(b) Sodium, potassium and lithium are stored under oil
- Reason : Sodium, potassium and lithium are most reactive when exposed to air, they reacts with water moisture present in air. To prevent air to come in contact with water they are stored under oil.
(c) Aluminium is a highly reactive metal, yet it is used to make utensils for cooking
- Reason : Aluminum reacts with oxygen and forms aluminum oxide layer on itself, which prevent it from contacting with other elements and compounds.
(d) Carbonate and sulphide ores are usually converted into oxides during the process of extraction.
- Reason : During extraction of metal some metal are present in carbonate and sulphide forms, but it is easy to obtain metal from its oxide. by roasting sulphides and by calcination on carbides, oxide can be formed.
(13) 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 :
Lemon or tamarind is sour means they contain acid. Tarnished copper vessels have oxide formed on it. When these acid substances used for cleaning the reaction between oxide and acid happen. When makes the copper metal cluster like new.
(14) Differentiate between metal and non-metal on the basis of their chemical properties.
Answer :
(1) Metal is able to conduct electricity due to presence of free electron. Non metal does not conduct electricity.
(2) Metal is usually solid at room temperature, but non metal are usually liquid or gas at room temperature.
(3) When metal form oxide it is basic in nature (MgO), but when non metal forms oxide it is acidic in nature(CO2).
(15) 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 Bangle 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 :
Gold, silver and platinum are less reactive metals. Even HCl can not harm the gold. Nitric acid is highly corrosive acid which can harm but the mixture he had was one third solution of hydrochloric acid to nitric acid.
(16) Give reasons why copper is used to make hot water tanks and not steel (an alloy of iron).
Answer :
Iron tank get corroded by hot water steam and forms iron oxide. But in case of copper, it is less reactive metal and does not react with hot water steam. Hence copper is used to make hot water tanks.
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