Give an example of a metal which
(i) is a liquid at room temperature.
(ii) can be easily cut with a knife.
(iii) is a good conductor of heat.
(iv) is a poor conductor of heat.
Explain the meanings of malleable and ductile.
Why is sodium kept immersed in kerosene oil?
Write the equations for the reactions of
(i) iron with steam.
(ii) calcium and potassium with water.
Sample of four metals A, B, C and D were taken added to the following solutions one by one. The observations made are tabulated below:
Use the table above and answer the following questions about metals A, B, C, and D.
(i) Which is the most active metal?
(ii) What would be observed if B is added to a solution of copper (II) sulphate?
(iii) Arrange the metals A, B, C and D in order of decreasing reactivity.
Which gas is produced when dilute hydrochloric acid is added to a reactive metal? Write the chemical reaction when iron reacts with dil.
What would you observe when zinc is added to a solution of iron (II) sulphate? Write the chemical reaction that takes place.
(i) Write the electron dot structure for sodium, oxygen and magnesium.
(ii) Show the formation of and by the transfer of electrons.
(iii) What are the ions present in these compounds?
Why do ionic compounds have high melting points?
Define the following terms:
Name two metals which are found in nature in the free state.
What chemical process is used for obtaining a metal from its oxide?
Metallic oxides of zinc, magnesium and copper were heated with the following metals:
In which cases will you find displacement reactions taking place?
Which metals does not corrode easily?
What are alloys?
Which of the following pairs will give displacement reactions?
1. solution and copper metal
2. solution and aluminium metal
3. solution and silver metal
4. solution and copper metal
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
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
Food cans are coated with tin and not with zinc because
1. zinc is costlier than tin
2. zinc has a higher melting point than tin
3. zinc is more reactive than tine
4. zinc is less reactive than tin
You are given a hammer, a battery, a bulb, wires and a switch.
(i) How would you use them to distinguish between samples of metals and non-metals?
(ii) Asses the usefulness of these tests in distinguishing between metals and non-metals.
What are amphoteric oxides? Give two examples of amphoteric oxides.
Name two metals which will displace hydrogen from dilute acids and two metals which will not.
In the electrolytic refining of a metal M, what would you take as the anode, the cathode and the electrolyte?
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 the diagram.
(i) What will be the action of the gas on
(a) dry blue litmus paper?
(b) moist blue litmus paper?
(ii) Write a balanced chemical equation for the reaction taking place.
State two ways to prevent the rusting of iron.
What type of oxides are formed when non-metals combine with oxygen?
(i) Platinum, gold and silver are used to make jewellery.
(ii) Sodium, potassium and lithium are stored under oil.
(iii) Aluminium is a highly reactive metal, yet it is used to make utensils for cooking.
(iv) Carbonate and sulphide ores are usually converted into oxides during the process of extraction.
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?
Differentiate between metals and non-metals on the basis of their chemical properties.
A man went 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?
Give reasons, why copper is used to make hot water tanks and not steel (an alloy of iron)?
Metals are refined by using different methods. Which of the following metals are refined by electrolytic refining?
A piece of granulated zinc was dropped into copper sulphate solution. After sometime, the colour of the solution changed from blue to colourless. Why?
Name a solvent in which electrovalent compounds are soluble and a solvent in which they are insoluble.
How do metals and non-metals combine?
What is anode mud?
Name a metal which is non-lustrous and a non-metal which is lustrous.
Which of the following metals will melt at body temperature ? Gallium, magnesium, caesium and aluminium.
A cleaned aluminium foil was placed in an aqueous solution of zinc sulphate. When the aluminium foil was taken out of the zinc sulphate solution after 15 minutes, its surface was found to be coated with a silvery grey deposit. From the given observation, what can be concluded?
Name two metals which react with dil. HNO3 to evolve hydrogen gas.
Arrange the following metals in the decreasing order of reactivity Na, K, Cu and Ag.
Show the electron transfer in the formation of MgCl2 from its elements.
Although metals form basic oxides, name one metal which forms an amphoteric oxide.
Name one property which is not shown by ionic compounds.
Name one metal which reacts neither with cold water, nor with hot water, but reacts with steam to produce hydrogen gas.
Name the metals which are usually alloyed with gold to make it harder.
What is meany by 22 carat gold?
Name any two alloys whose electrical conductivity is less than that of pure metals.
Can rusting of iron nail occur in distilled water?
Name an alloy that contains a non-metal as one of its constituents.
Name an alloy which has mercury as one of its constituents.
Name two metals that are obtained by electrolysis of their chlorides in molten form.
Why does calcium float in water?
Why is tungsten metal selected for making filaments of incandescent lamp bulbs?
A green layer is gradually formed on a copper plate left exposed to air for a week in a bathroom. What could this green substance be?
Explain what happens if bauxite containing iron and silica as impurities is directly subjected to the process of electrolytic reduction without prior purification.
Generally, when metals are treated with mineral acids, hydrogen gas is liberated but when metals (except Mn and Mg) are treated with HNO3, hydrogen is not liberated, why?
A non-metal X exists in two different forms Y and Z. Y is the hardest natural substance, whereas Z is a good conductor of electricity. Identify X, Y and Z.
Name a metal which
(i) is a good conductor of heat.
(ii) has a very low melting point.
(iii) does not react with oxygen even at high temperature.
(iv) is most ductile
Give reason for the following:
(i) School bells are made up of metals.
(ii) Electrical wires are made up of copper.
Would it be right to store
(i) a solution of ZnSO4 in Pb vessel?
(ii) a solution of AgNO3 in Cu vessel?
Why sodium chloride has a high melting point?
Why is that sodium when react with water form sodium form only aluminium oxide?
(i) If vapour of dry ammonia gas are brought in contact with red litmus strip, what will happen to the colour of the litmus strip?
(ii) Name the metal whose foils are used for the packing of food materials.
Give the formulae of the stable binary compounds that would be formed by the combination of the following pairs of elements.
(i) Mg and N2 (ii) Li and O2
(iii) Al and Cl2 (iv) K and O2
Why the reduction process is always involved in the extraction of metals?
What happens when
(i) is heated in the absence of oxygen?
(ii) a mixture of and is heated?
Compound X and aluminium are used to join railway tracks.
(i) Identify the compound X.
(ii) Name the reaction.
(iii) Write the equation for it.
A non-metal A is an important constituent of our food and forms two oxides B and C. Oxide B is toxic whereas C causes global warming.
(i) Identify A, B and C.
(ii) To which group of periodic table does A belong?
An element E combines with O2 to form an oxide E2O, which is a good conductor of electricity. Answer the following:
(i) How many electrons will be present in the outermost shell of E?
(ii) Write the formula of the compound formed when it combines with chlorine.
Royal water is prepared by mixing two acids A and B. It can dissolve gold and platinum. It is highly corrosive and fuming liquid. Identify A and B. What is the ration in which A and B are mixed?
A metal M does not liberate hydrogen from acids but reacts with oxygen to give a black coloured product. Identify M and black coloured product and also explain the reaction of M with oxygen.
A metal that exists as a liquid at room temperature is obtained by heating its sulphide in the presence of air. Identify the metal and its ore and give the reaction involved.
Brass is preferred to stainless steel for door settings. Give reason.
Alloys are used in electrically heating devices rather than pure metals. Give reasons.
Corrosion is a serious problem. Every year an enormous amount of money is spent to replace damaged iron. What steps can be taken to prevent this damage? What will learners infer from this information?
Explain how the properties of an alloy are different from those of constituent metals.
State which of the following chemical reactions will take place or not, giving suitable reason for each?
During extraction of metals, electrolytic refining is used to obtain pure metals.
(i) Which material will be used as anode and cathode for refining of silver metal by this process?
(ii) Suggest a suitable electrolyte also.
(iii) In this electrolytic cell, where do we get pure silver after passing electric current?
Cheshta, a 10th class student was asked to identify iron, copper, zinc and aluminium only by observing the effect of the action of concentrated nitric acid and caustic soda on each metal. How did she put the reactions of these metals with each of the reagents?
Explain the reactions of different metals with hot water, cold water and steam. Give one example with a proper balanced chemical equation. Name two metals which do not react with any form of water.
State the property utilised in the following:
(i) Graphite in making electrodes.
(ii) Electrical wires are coated with Polyvinyl Chloride (PVC) or a rubber-like material.
(iii) Metal alloys are used for making bells and strings of musical instruments.
Show the formation of MgO by the transfer of electrons in the two elements using electron dot structures.
Atomic number of Mg is 12 and of oxygen is 8. Show the formation of MgO from its elements.
Using the electronic configurations, explain how magnesium atom combines with oxygen atom to form magnesium oxide by transfer of
(i) Write any two properties of ionic compounds.
(ii) Show the formation of aluminium chloride by the transfer of electrons between the atoms. (Atomic number of aluminium and chlorine
are 13 and 17 respectively).
A student was given Mg, Zn, Fe and Cu metals. He puts each of them in dil. HCl contained which of them
(i) will not displace H2 from dil. HCl?
(ii) will give H2 with 5% HNO3?
(iii) will be displaced from its salt solution by all other metals?
Mercury is the only metal found in the liquid state. It is largely used in thermometers to measure the temperature, but mercury is a
very dangerous metal as its density is very high. What two precautions would you take while handling the equipments containing mercury? What will learners infer from the above information?
An ore on heating in air produces sulphur dioxide.
(i) Which process would you suggest for its concentration?
(ii) Describe briefly any two steps involved in the conversion of this concentrated ore into related metal.
A metal A, which is used in thermite process, when heated with oxygen gives an oxide B, which is amphoteric in nature. Identify A and B. Write down the reactions of oxide B with HCl and NaOH.
Two ores A and B were taken. On heating, ore A gives CO2, whereas ore B gives SO2. What steps will you take to convert them into metals?
A metal acts as a good reducing agent. It reduces and The reaction with is used for joining broken railways tracks. Identify the metal and write all the chemical reactions.
An element A reacts with water to form a compound B which is used in white washing. The compound B on heating forms an oxide C which on treatment with water gives back B. identify A, B and C and give the reactions involved.
An alkali metal A gives a compound B (molecular mass=40) on reacting with water. The compound B gives a soluble compound C on treatment with aluminium oxide. Identify A, B and C and give the reactions involved.
P, Q and R are 3 elements which undergo chemical reactions according to the following equations:
Answer the following questions:
(i) which element is most reactive?
(ii) Which element is least reactive?
(iii) State the type of reaction listed above.
A yellow coloured powder X is soluble in carbon disulphide. It burns with a blue flame forming suffocating smelling gas which turns moist blue litmus red. Identify X and give chemical reaction. Identify whether it is a metal or a non-metal?
Hydrogen is not a metal but it has been assigned a place in the reactivity series of metals. Explain.
Describe an activity to show how the following metals can be arranged in the decreasing order of reactivity with dil.sulphuric acid: Al, Zn, Cu, Fe, Mg?
Explain the process of electrolytic refining for copper with the help of a labelled diagram.
What is meant by electrolytic reduction? How is sodium obtained from its molten chloride? Explain.
With the help of a suitable example, explain how ionic compounds are formed? State any three general properties of ionic compounds.
(i) Predict the reaction, if any, between
(a) zinc and silver nitrate solution,
(b) magnesium and iron (II) chloride solution,
(c) copper and magnesium sulphate solution.
Write the equation, with its physical form symbols, for the reaction.
(ii) A lump of element X can be cut by a knife. During its reaction with water, X floats and melts. What is X? Explain.
In what forms are metals found in nature? With the help of examples, explain how metals react with oxygen, water and dilute acids. Also, write chemical equations for the reactions.
Choose from the following metals to answer the questions below:
Aluminium, calcium, copper, iron, magnesium, potassium, nickel and zinc
Name a metal which
(i) is manufactured by the electrolysis of its molten oxide.
(ii) is used to galvanise iron.
(iii) is alloyed with zinc to make brass.
(iv) reacts with aqueous copper (II) sulphate to give a pink solid.
(v) does not react with cold water.
(i) Given below are the steps for extraction of copper from its ore. Write the reaction involved.
(a) Roasting of copper (I) sulphide.
(b) Reduction of copper (I) oxide with copper (I) sulphide.
(c) Electrolytic refining.
(ii) Draw a neat and well labelled diagram for electrolytic refining of copper.
How is copper obtained from its ore ? Write only the chemical equations. How is copper thus obtained refined? Name and explain the process along with a labelled diagram.
(i) Give differences between roasting and calcination with suitable examples.
(ii) Explain how the following metals are obtained from their compounds by the reduction process.
(a) Metal M which is in the middle of the reactivity series.
(b) Metal N which is high up in the reactivity series.
Give one example of each type.
Give reasons for the following:
(i) Ionic compounds have higher melting and boiling points.
(ii) Sodium is kept immersed in kerosene.
(iii) Reaction of calcium with water is less violent.
(iv) Prior to reduction the metal sulphides and carbonates must be converted into metal oxides for extracting metals.
Give reasons for the followings:
(i) Generally no hydrogen gas is evolved when metals react with dilute nitric acid.
(ii) Sodium hydroxide solution cannot be kept in aluminium containers.
(iii) Silver metal does not combine easily with oxygen but silver jewellery tarnishes after some time.
(iv) Sodium is obtained by the electrolysis of its molten chloride and not from its aqueous solution.
(v) Aluminium reacts with dilute hydrochloric acid slowly in the beginning.
10 mL of freshly prepared iron sulphate was taken in each of four test tubes. Strips of copper, iron, zinc and aluminium was introduced, each metal in a different test tube. A residue was obtained in two of them. Which of these metals will form the precipitates?
On placing a piece of zinc metal in a solution of mercuric chloride, it acquires a shining silvery surface but when it is placed in a solution of magnesium sulphate, no change is observed. Give reason.
A copper coin is kept immersed in silver nitrate solution for some time. What change will take place in the coin and colour of the solution? Write the chemical equation for the reaction involved.
A lady bought a new iron container and kept blue vitriol solution into it. On the next day, she found that the blue colour of the solution fades. She went to the shopkeeper and complained.
But the shopkeeper argued that the container is of good quality and he refused to return the money. An aware person Ankit came there and asked the matter and told the lady that the container is of good quality and you have kept the wrong substance in it, so the fault is all yours.
On the basis of given passage, answer the following questions.
(i) Why the container becomes porous when blue vitriol solution is kept into it?
(ii) What qualities are exhibited by Ankit?
Gold is a very precious metal. Pure metal is very soft therefore, it is not suitable for making jewellery. It is alloyed with either silver or copper to make it hard but sometimes jewellers mix a large quantity of copper and silver in gold to earn more profit.
Read the above passage and answer the following questions.
(i) What precautions should you take while purchasing gold jewellery?
(ii) Why does the government insist on purchasing hallmarked jewellery?
(iii) What value is associated with the given passage?
One day Madhu visited an aluminium industry with her father She found that molten alumina was taken in the fused state for electrolytic reduction process. She asked her father the reason for using fused alumina as an electrolyte instead of the solution of aluminium salt, although the latter can save ample amount of energy. Madhu's father was pleased with her concern for saving energy, hence he explained to her why nothing could be done about that wastage of energy in that particular instance. What could be his explanation? What values do you infer from this passage?