Metals and Non-Metals: Class 10 Science Q&A · Page 5
114 free answers on Metals and Non-Metals (Science) for Class 10 students, across CBSE, ICSE and State boards.
Question & Answer
Questions
- ScienceClass 10CBSE
Which one of the following metals do not react with cold as well as hot water? (a) Na (b) Ca (c) Mg (d) Fe
Soln: Answer is (d) Fe Explanation: Sodium and Calcium reacts vigorously with water and Magnesium reacts with hot water to form Magnesium Oxide. Iron does not react with cold and hot water but it reacts with steam.
- ScienceClass 10CBSE
Aluminium is used for making cooking utensils. Which of the following properties of aluminium are responsible for the same? (i) Good thermal conductivity (ii) Good electrical conductivity (iii) Ductility (iv) High melting point (a) (i) and (ii) (b) (i) and (iii) (c) (ii) and (iii) (d) (i) and (iv)
Soln: Answer is (d) (i) and (iv) Explanation: Ductility and electric conductivity has no relation to cooking hence thermal conductivity and high melting point are the right answers.
- ScienceClass 10CBSE
1. The ability of metals to be drawn into thin wire is known as (a) ductility (b) malleability (c) sonorousity conductivity
Soln: Answer is (a) ductility Explanation: Ductility is property of metals to be drawn into thin Malleability is property of metals to be drawn into thin wire Sonorousity is the ability of metal to be sonorous in nature Conductivity is the ability to conduct electricity
- ScienceClass 10CBSE
Which of the following property is generally not shown by metals? (a) Electrical conduction (b) Sonorous in nature (c) Dullness Ductility
Soln: Answer is (c) Dullness
- ScienceClass 10CBSE
Give reasons why copper is used to make hot water tanks and not steel (an alloy of iron).
Solution: Copper is used to make hot water tanks and not steel (an alloy of iron) because copper does not react with either water or steam, whereas iron reacts with steams to corrode the tank.
- ScienceClass 10CBSE
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?
Solution: The goldsmith used a solution called Aqua regia which is referred to as royal water in Latin. It is the mixture of concentrated hydrochloric acid and concentrated nitric acid in the ratio of 3:1. Aqua regia is capable of dissolving noble metals like gold and platinum. When upper-layer of dull gold ornament is dissolved they lose their weight.
- ScienceClass 10CBSE
Differentiate between metal and non-metal on the basis of their chemical properties.
Metals Non-metals When metals are heated with oxygen, they form ionic oxides which are basic in nature and form bases on dissolving with water. This turn red litmus paper to blue. When non-metals are heated with oxygen, they form covalent oxides which are acidic in nature, which form acid on dissolving with water. This
- ScienceClass 10CBSE
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.
Solution: Tarnished copper vessels are cleaned with lemon or tamarind because this sour substance contains acids which dissolve the coating of copper oxide or basic copper carbonate present on the surface or tarnished copper vessels. This makes them shining red-brown again. Hence, they are very effective in cleaning tarnished copper vessels.
- ScienceClass 10CBSE
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
(a) Platinum, gold and silver are used to make jewellery as these metals are very less reactive. Hence, they are not affected by air, water or most chemicals. These metals have a lot of luster and they are malleable and ductile in nature, and also high corrosion resistance in nature. (b) Sodium, potassium and lithium readily react with water to produce a lot of heat. As a result, hydrogen evolved in the reaction results in a fire. On exposure to water they rea
- ScienceClass 10CBSE
What type of oxides are formed when non-metals combine with oxygen?
Solution: When non-metals combine with oxygen they form either acidic or neutral oxides. Ex: N2O5 or N2O3 is an acidic oxide; CO is a neutral oxide.
- ScienceClass 10CBSE
State two ways to prevent the rusting of iron.
Solution: Iron can be prevented from rusting by coating the surface of the iron with rust proof paints By applying oil/grease on the surface of iron objects as it will prevent the iron surface to get in contact with air consisting of moisture.
- ScienceClass 10CBSE
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.
Solution: a) When sulphur powder is burnt in the air sulphur-di-oxide is formed. (i) Sulphur-di-oxide does not have any effect on dry litmus paper. (ii) Sulphur-di-oxide turn the moist litmus paper from blue to red as contact of SO2 with water turns to sulfurous acid. (b) S(s) + O2(g) → SO2(g) SO2(g) + H2</su
- ScienceClass 10CBSE
In the electrolytic refining of a metal M, what would you take as the anode, the cathode and the electrolyte?
Solution: In the process of electrolytic refining of metal called ‘M’, an impure and thick block of metal M is considered an anode, a thin strip or wire of pure metal M is taken as cathode. A suitable salt solution of metal M is considered as the electrolyte.
- ScienceClass 10CBSE
Name two metals which will displace hydrogen from dilute acids, and two metals which will not.
Solution: Zinc (Zn) and Magnesium (Mg) are the two metals which will displace hydrogen from dilute acids as they are very reactive metals. Gold (Au) and Silver (Ag) are the metals which will not replace hydrogen from dilute acids as these metals are less reactive.
- ScienceClass 10CBSE
What are amphoteric oxides? Give two examples of amphoteric oxides.
Solution: Oxides that react with both acids and bases to form salt and water are known as amphoteric oxides. Examples: PbO and Al2O3. Amphoteric oxides are the one which react with both acids and bases to form salt and water. Examples: Lead oxide – PbO and Aluminium oxide – Al2O3.
- ScienceClass 10CBSE
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.
Metals are malleable and can be easily drown into sheets by hitting with hammer. On the other hand, if we beat non-metals they break down and they cannot be drawn into sheets as they are non-malleable. Metals are good conductors of electricity, hence they make bulb when you connect metals with a battery, wire and bulb. Similarly, if non-metals are bad conductors of electricity, they fail to light up the bulb on connecting with wire and battery. These
- ScienceClass 10CBSE
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.
Solution: Answer is c. Food cans are coated with tin and not with zinc because zinc is more reactive, that is electro positive than tin.
- ScienceClass 10CBSE
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
Solution: Correct answer is option (a) Calcium. Calcium reacts with oxygen to give calcium oxide. Calcium oxide is soluble in water to give Calcium Hydroxide. Carbon forms carbon-oxide with oxygen which is gas, hence option B is wrong Silicon reacts with oxygen and forms silicon dioxide. This is insoluble in water. So option C is not correct. Iron reacts with oxygen and forms Iron
- ScienceClass 10CBSE
Which of the following methods is suitable for preventing an iron frying pan from rusting? 1. Applying grease 2. Applying paint 3. Applying a coating of zinc 4. All of the above
Answer is (c) Applying a coat of zinc Though applying grease and applying paint do prevent iron from rusting, we cannot apply these methods on a frying pan. Hence, applying a coat of zinc is the most appropriate method to prevent an iron pan from rusting.
- ScienceClass 10CBSE
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
Solution: Option d i.e., AgNO3 solution and copper is the correct answer. Copper displaces the silver cations (reducing them to the elemental metal), in the process copper itself is being oxidised to Copper II cations (Cu2+) and going into solution. So silver metal is seen precipitating out and a copper II nitrate solution will remain. Cu(s) + 2AgNO3 (aq) → Cu(NO3)2 (aq) + 2Ag (s)<