Q 1 – The most abundant metal in the earth’s crust is
(a) Iron
(b) Aluminium
(c) Calcium
(d) Sodium
(b) Aluminium
Q 2 – Why do shopkeepers apply oil on tools made of iron while storing them?
We apply oil on Iron tools kept in a storage because to prevent it from corrosion and rusting.
Q 3 – Which of the following is the correct arrangement of the given metals in ascending order of their reactivity?
Zinc, Iron, Magnesium, Sodium
(a) Zinc > Iron > Magnesium > Sodium
(b) Sodium > Magnesium > Iron > Zinc
(c) Sodium > Zinc > Magnesium > Iron
(d) Sodium > Magnesium > Zinc > Iron
(d) Sodium > Magnesium > Zinc > Iron
Q 4 – Which of the following oxide(s) of iron would be obtained on prolonged reaction of iron with steam?
(a) FeO
(b) Fe2O3
(c) Fe3O4
(d) Fe2O3 and Fe2O4
(c) Fe3O4
Q 5 – The poorest conductor of heat among metals is
(a) Lead
(b) Mercury
(c) Calcium
(d) Sodium.
(a) Lead
Q 6 – The electronic configurations of three elements X, Y and Z are X – 2, 8; Y – 2, 8, 7 and Z 2, 8, 2. Which of the following is correct?
(a) X is a metal
(b) Y is a metal
(c) Z is a non-metal
(d) Y is a non-metal and Z is a metal
(d) Y is a non-metal and Z is a metal
Q 7 – Which of the given properties is generally not shown by metals?
A. Electrical conduction
B. Sonorous in nature
C. Dullness
D. Ductility
C. Dullness
Q 8 – Which property of metals is used for making bells and strings of musical instruments like Sitar and Violin?
(a) Sonorous nature
(b) Malleability
(c) Ductility
(d) Conductivity
(a) Sonorous nature
Q 9 – The non-metal which is liquid at room temperature is:
(a) Mercury
(b) Bromine
(c) Carbon
(d) Helium
(b) Bromine
Q 10 – Name the gas in air which tarnishes silver particles slowly.
Hydrogen sulphide gas
Q 11 – What happens when a solution of an acid is mixed with a solution of a base in a test tube?
(i) Temperature of the solution decreases
(ii) Temperature of the solution increases
(in) Temperature of the solution remains the same
(iv) Salt formation takes place
(a) (i) and (iv)
(b) (i) and (iii)
(c) (ii) only
(d) (i) and (iv)
(d) (i) and (iv)
Q 12 – In terms of acidic strength, which one of the following is in the correct increasing order?
(a) Water < Acetic acid < Hydrochloric acid
(b) Water < Hydrochloric acid < Acetic acid
(c) Acetic acid < Water < Hydrochloric acid
(d) Hydrochloric acid < Water < Acetic acid
(a) Water < Acetic acid < Hydrochloric acid
Q 13 – Which of the following non-metal is lustrous?
(a) Sulphur
(b) Oxygen
(c) Nitrogen
(d) Iodine
(d) Iodine
Q 14 – Expand PVC.
Q 15 – Oxides of moderately reactive metals like Zinc, Iron, Nickel, Tin, Copper etc. are reduced by using
(a) Aluminium as reducing agent
(b) Sodium as reducing agent
(c) Carbon as reducing agent
(d) Calcium as reducing agent
(c) Carbon as reducing agent
Q 16 – At what temperature is gypsum heated to form Plaster of Paris?
(a) 90°C
(b) 100°C
(c) 110°C
(d) 120°C
(b) 100°C
Q 17 – The chemical name and formula of baking powder are:
(a) sodium chloride (NaCl)
(b) sodium bicarbonate (NaHCO3)
(c) sodium carbonate (Na2CO3)
(d) sodium sulphate (Na2SO4)
(b) sodium bicarbonate (NaHCO3)
Q 18 – Alkalis are
(a) acids, which are soluble in water
(b) acids, which are insoluble in water
(c) bases, which are insoluble in water
(d) bases, which are soluble in water
(d) bases, which are soluble in water
Q 19 – Why does calcium float in water?
Calcium reacts with water to form calcium hydroxide and hydrogen. Bubbles of hydrogen gas stick to the surface of calcium, hence it floats.
Q 20 – Metals have a shining surface in their pure state. Give a reason for the same.
Metals have unique ability to reflect light from their pure surface (without impurities). This results in a shining surface. This property is known as lustre.
Q 21 – Give an example of an elementary substance which is a good conductor of electricity but is not a metal.
Graphite (an allotrpoe of carbon) is a well known nonmetal which is a very good conductor of electricity.
Q 22 –Define Aqua Regia. What are its uses ?
Aqua-Regia is a freshly prepared mixture of 1 part of concentrated nitric acid and 3 parts of concentrated hydrochloric acid.
Aqua-Regia can dissolve all metals. For example, aqua-Regia can dissolve even gold and platinum metals (through concentrated nitric acid or concentrated hydrochloric acid alone cannot dissolve gold or platinum metals).
Q 23 – State reasons for the following:
(i) Electric wires are covered with rubber-like material.
(ii) From dilute hydrochloric acid, zinc can liberate hydrogen gas but copper cannot.
(i) It is because rubber is an insulator and does not allow current to flow
through it.
(ii) Zinc is placed above hydrogen in the reactivity series of metals while copper
is placed below it. Metals placed above hydrogen can displace hydrogen from
water and acids while those below it cannot. Therefore, zinc can displace
hydrogen from dilute HCl whereas copper cannot.
Q 24 – Name two metals which can be used to reduce metal oxides to metal.
Q 25 – A metal M is found in nature as MCO3. It is used in galvanizing iron articles. Name the metal M .
Zinc (Zn)
Q 26 – Differentiate between Ionic Compounds and Covalent Compounds ?
| Ionic compounds | Covalent compounds |
| 1. Ionic compounds are usually crystalline solids. | Covalent compounds are usually liquids or gases. Only some of them are solids. |
| 2. Ionic compounds have high melting points and boiling points. That is, ionic compounds are non volatile. | Covalent compounds have usually low melting points and boiling points That is, covalent compounds are usually volatile. |
| 3. Ionic compounds conduct electricity when dissolved in water or melted. | Covalent compounds do not conduct electricity. |
| 4. Ionic compounds are usually soluble in water. | Covalent compounds are usually insoluble in water (except, glucose, sugar, urea, etc.) |
Q 27 –What are Amphoteric Oxides? Illustrate with reactions how Zinc and Aluminium are behaving as Amphoteric in Nature .
The oxides which behave as both acidic and basic oxides are called amphoteric oxides. Examples- aluminium oxide (Al2O3), zinc oxide (ZnO).
Q 28 –In the formation of compound between two atoms A and B, A loses two electrons and B gains one electron.
(a) What is the nature of the bond between A and B?
(b) Suggest the formula of the compound formed between A and B.
(c) On similar lines explain the formation of MgCl2 molecule.
(d) Common salt conducts electricity only in the molten state. Why?
(e) Why is melting point of NaCl high?
(C) Na+ and Cl¯are free to move in molten state but not in solid state.
(d) It is due to strong force of attraction between Na+ and Cl¯.
Q 29 – Give one most suitable word for the following statements:
- Metal oxides which show basic as well as acidic behaviour.
- Iodine, a shining non-metal.
- Amphoteric oxides.
- Lustrous
Q 30 – Why oxides of highly reactive metals cannot be reduced by carbon
It is because highly reactive metals themselves are good reducing agents, so they can’t be reduced by carbon.
Q 31 – Give reason why: Electric wires are coated with plastic.
Plastic is a non-conductor of electricity, therefore electric wires are coated with plastic.
Q 32 – It nature, aluminium is found in combined state whereas silver/gold are found in free state. Give reaso
Aluminium is reactive metal, therefore it is found in combined state whereas silver/gold are less reactive (noble) metals and so are found in free state.
Q 33 – Write one example of each of a. a metal which is so soft, that it can be cut with a knife and a non-metal which is the hardest known substance. b. a metal and a non-metal which exist as liquid at room temperature.
- Sodium is so soft that it can be easily cut with a knife.
- Diamond is the allotrope of carbon, which is the hardest known substance and a non-metal.
- Mercury is a metal and Bromine is a nonmetal which are found in liquid state at room temperature.
Q 34 – Why is sodium chloride soluble in water but not in kerosene?
Sodium chloride is the ionic compound and it form ions in water, therefore it is soluble in water whereas kerosene is a non-polar covalent compound, NaCl does not form ions in kerosene, therefore, it is insoluble in it.
Q 35 – A compound Z is formed by transfer of electrons from the metal X to a non-metal Y, Identify the type of bond formed in the compound. List three properties of compound formed by such type of bonds
The bond formed is ionic bond:
- The compound will have high melting and boiling point.
- It will be soluble in water.
- It will conduct electricity in molten state as well as in aqueous solution.
Q 36 – Why is iron galvanised with zinc? Can it be galvanised with copper? If not, why?
Iron is galvanised by zinc because zinc is more reactive than Fe. Iron cannot be galvanised by copper because copper is less reactive than iron and therefore iron itself gets corroded when coated with copper.
Q 37 – The way, metals like sodium, magnesium and iron react with air and water is an indication of their relative positions in the ‘reactivity series’. Is this statement true?
Yes, Na reacts vigorously with cold water because it is highly reactive.
Magnesium reacts with hard water because it is less reactive than sodium. Iron reacts only with steam because it is less reactive than Mg:
2Na(s) + MgO(s) → Na2 O(s) + Mg
3Mg + Fe2 O3 → 3MgO + 2Fe.
Q 38 – a. What is an alloy? How is it prepared? Give two examples of alloys.
b. Iron is not used in pure state. Give reason.
a. Alloy is a homogeneous mixture of two or more metals. One of them can be a non-metal also. Alloys are made by melting two metals together and then cooling it. Example: Brass and Bronze
b .Iron gets rusted, therefore it is not used in pure state.
Q 39 – Name two metalloids.
- Boron,
- silicon
Q 40 – Name a metal which is stored under kerosene and belongs to fourth period of the periodic table.
Sodium metal is stored in kerosene. It is because it is so reactive that it reacts vigorously with oxygen of air.
Q 41– A non-metal A which is the largest constituent of air, when heated with H2 in 1:3 ratio in the presence of catalyst (Fe) gives a gas B. On heating with O2 it gives an oxide C. If this oxide is passed into water in the presence of air it gives an acid D which acts as a strong oxidising agent.
(a) Identify A, B, C and D
(b) To which group of periodic table does this non-metal belong?
(a) Non-metal “A” is nitrogen because it is the largest constituent of air which constitute around 78% of the gases. When heated with H2 in 1:3 ratio in the presence of a catalyst (Fe) following reaction takes place. Therefore, B is Ammonia. Therefore, C is Nitrogen dioxide.
Q 42 – Generally, when metals are treated with mineral acids, hydrogen gas is liberated but when metals (except Mn and Mg), treated with HNO3, hydrogen is not liberated, why?
Most of the metals do not react with HNO3 because nitric acid is a strong oxidising agent. Hence, when metals (except Mn and Mg) are treated with nitric acid; hydrogen gas is not liberated. Only magnesium and manganese can produce hydrogen gas with very dilute nitric acid.
Q 43 – When a metal X is treated with cold water, it gives a basic salt Y with molecular formula XOH (Molecular mass = 40) and liberates a gas Z which easily catches fire. Identify X, Y and Z and also write the reaction involved.
(Na) and potassium (K) react with cold water to form basic salt NaOH and KOH respectively. The molecular mass of NaOH is 40. So, X is Na and Y is NaOH.
Q 44 – A metal M does not liberate hydrogen from acids but reacts with oxygen to give a black colour product. Identify M and black coloured product and also explain the reaction of M with oxygen.
Copper does not react with acids. But copper gives black coloured copper oxide when it reacts with oxygen. Hence, M is copper and black coloured product is copper oxide.
2 Cu + O2→2 CuO
Q 45 – A solution of CuSO4 was kept in an iron pot. After few days the iron pot was found to have a number of holes in it. Explain the reason in terms of reactivity. Write the equation of the reaction involved.
Iron is more reactive than copper. Due to this, iron displaced copper from copper sulphate to form iron sulphate. A portion of the iron pot got dissolved in this process and caused holes in it. Following equation is involved in this reaction:
CuSO4 + Fe → FeSO4 + Cu
Q 46 – 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 reaction involved
A is sodium because molar mass of NaOH is 40; which can be shown as follows:
Na(23)+O(16)+H(I)=40
So. B is NaOH
When sodium hydroxide is treated with aluminium oxide, we get sodium aluminate. So, C is sodium aluminate. Following reaction happens in this case:
Al2O3 + 2NaOH →2NaAlO2+H2O
Q 47 – Iqbal treated a lustrous, divalent element M with sodium hydroxide. He observed the formation of bubbles in reaction mixture. He made the same observations when this element was treated with hydrochloric acid. Suggest how can he identify the produced gas? Write chemical equations for both the reactions.
Its A Divalent Element And Lustrous So Its A Metal
Second Thing Only Very Reactive Metals React With Sodium Hydroxide.
Very Reactive Metals React With Sodium Hydroxide To Give Hydrogen Gas.
Now He Can Identify It By Bringing A Burning Candle He Would See That Gas Burns With A Pop Sound.
There Are Possible Metals Are
Calcium And Magnesium And Zinc And Many More
These Are Possible.
Now Reaction Could Be
Ca + NaOH———–> Salt+ Hydrogen
Mg + NaOH————> Salt + Hydrogen
Zn + NaOH———-> Salt + Hydrogen
All Of Them Give Complex Salts.
When They React With HCl They Give Their Respective Chlorides With H2 Gas
Q 48 – How would you distinguish between baking powder and washing soda by heating?
Baking soda (NaHCO3) gives carbon dioxide and water vapour on heating at very low temperature. The gas so formed turns lime water milky, which confirms the presence of carbon dioxide gas.
When washing soda (Na2CO3) is heated it does not produce carbon dioxide even at high temperatures, but gives off its water of crystallisation to become anhydrous salt.
