CBSE Class 10 Science HOTs Metals and Non Metals

METALS & NON-METALS

Question : The metallic lustre exhibited by sodium is explained by :
(B) oscillation of mobile
(A) diffusion of sodium ions valence electrons
(C) existence of free protons
(D) existence of body centered cubic lattice
Answer : B

Question : Which of the following will appears silvery white ?
(A) Li
(B) K
(C) Na
(D) All
Answer : D

Question : Which of the following s-block metal does not react with water ?
(A) K
(B) Na
(C) Ca
(D) Be
Answer : D

Question : Which of the following option is correct for given reaction ?
M + H₂SO₄ →
(A) It reacts vigrously with acid if M is alkali metal.
(B) It reacts readily with acid if M is alkaline earth metal.
(C) metal sulphate and hydrogen gas will form after reaction.
(D) All are correct.
Answer : D

Question : Be reacts with excess of caustic soda to form :
(A) Be(OH)₂
(B) BeO
(C) Na2[Be(OH)₄]
(D) Be(OH)₂.BeCO₃
Answer : C

Question. Which of the following can undergo a chemical reaction?
(a) MgSO₄ +Fe
(b) ZnSO₄ + Fe
(c) MgSO₄ + Pb
(d) CuSO₄ + Fe
Answer : D

Question. Which one of the following metals do not react with cold as well as hot water?
(a) Na
(b) Ca
(c) Mg
(d) Fe
Answer : D

Question. 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
Answer : D

Question. What happens when calcium is treated with water?
(a) It does not react with water
(b) It reacts violently with water
(c) It reacts less violently with water
(d) Bubbles of hydrogen gas formed stick to the surface of calcium
(a) (a) & (d)
(b) (b) & (c)
(c) (a) & (b)
(d) (c) & (d)
Answer : D

Question. The chemical reaction between a piece of copper and nitric acid is given by the chemical equations,
Cu + HNO₃ → Cu(NO₃)₂ + H₂
H₂ + HNO₃ → H₂O + NO₂
What can be inferred from the chemical equation?
(a) Copper causes the oxidation of HNO₃ to form NO₂.
(b) Hydrogen gas gets oxidized by HNO₃ to form water.
(c) gas reacts with oxygen in the air to form water.
(d) Nitrate reacts with hydrogen to form NO₂ and H₂O.
Answer : B

Question. Which of the given non-metal is a liquid?
(a) Hydrogen
(b) Bromine
(c) Chlorine
(d) Mercury
Answer : B

Question. An element reacts with oxygen to form an oxide which dissolves in dilute hydrochloric aci(d) The oxide formed also turns a solution of red litmus blue. The element will be ……
(a) metal
(b) nonmetal
(c) both a and b
(d) none of these.
Answer : A

Question. Paheli took some crystals of copper sulphate and heated it. After some time, she added water to the content of test tube.
The two visible changes observed here are
(a) blue crystals changes to white powder, on adding water it regains its blue colour.
(b) blue crystals changes to pale green, on adding water it regains its blue colour.
(c) No change
(d) blue crystals changes to white crystals and become colourless
Answer : A

Question. A student makes an electric circuit using an LED, a battery and connecting wires to test the conductivity of distilled water. The student notices that the LED does not glow.
He replaces the distilled water with a salt solution and observes that the LED glows. How does the salt solution help the LED to glow?
(a) Salt solution is covalent in nature and conducts electricity.
(b) Salt solution has a low melting point which allows the current to flow through it.
(c) Salt solution has a high boiling point which allows the flow of current in the circuit without getting hot.
(d) Salt solution contain ions which makes it conductive and allows the electricity to flow through it.
Answer : D

Question. Which acid is formed when sulphur dioxide dissolves in water?
(a) Sulphuric acid
(b) Sulphurous acid
(c) Sulphate acid
(d) Sulphonic acid
Answer : B

Question : What is [X] in the following reaction ?
MgCl₂.6H₂O →Δ  [X] + HCl + H₂O
(A) MgO
(B) Mg
(C) Mg(OH)₂
(D) Mg(OH)Cl.
Answer : A

Question : When magnesium burns in air, compounds of magnesium formed are magnesium oxide and :
(A) Mg₃N₂
(B) MgCO₃
(C) Mg(NO₃)₂
(D) Mg(NO₂)₂
Answer : A

Question : Products of following reaction :
NaOH + ZnO →
(A) Na₂O, Zn(OH)₂
(B) Na₂ZnO₂, H₂O
(C) Na₂O₂ , Zn(OH)₂
(D) None of these
Answer : B

Question : Products of the following reaction are : NaOH + S →
(A) Na₂S, Na₂S₂O₃ , H₂O
(B) Na₂SO₄, H₂O
(C) Na₂O₂, Na₂SO₄
(D) H₂S , Na₂SO₄
Answer : A

Question : Which of the following can not decompose on heating to give CO₂ in a dry test tube ?
(A) Li₂CO₃
(B) Na₂CO₃
(C) KHCO₃
(D) BeCO₃
Answer : B

Question : On addition of which metal, copper sulphate solution (blue colour) will be changed to colourless solution ?
(A) Fe
(B) Ag
(C) Zn
(D) Hg
Answer : C

Question : Which of the following will give displacement reaction ?
(A) NaCl solution and copper metal
(B) MgCl₂ solution and silver metal
(C) FeSO₄ solution and silver metal
(D) AgNO₃ solution and copper metal
Answer : D

Question : Which of the following is a volatile liquid ?
(A) Chlorine
(B) Fluorine
(C) Bromine
(D) Iodine
Answer : C

Question : Which one of the following statements pertaining to the general properties of metals is WRONG ?
(A) Most of the metals form basic oxides.
(B) All metals displace hydrogen from acids.
(C) The hydroxides of heavy metals are converted to their oxides upon ignition.
(D) Metals form alloys with other metals.
Answer : D

Question : _______ is/are added in alumina at the time of electrolysis.
(A) Na₃AlF₆
(B) CaF₂
(C) C
(D) (A) & (B) both
Answer : D

Question : The froth floatation process is based upon -
(A) The differences in the specific gravity of ore and gangue particles
(B) The magnetic properties of gangue and ore
(C) Preferential wetting of gangue particles by oil
(D) Preferential wetting of ore particles by oil
Answer : D

Question : In the metallurgy of copper , the impure metal got after Bessemerization is called :
(A) blister copper
(B) wrought copper
(C) brass copper
(D) pig copper
Answer : A

Question : Which oil is used as frother in froth floatation process ?
(A) Mustard oil
(B) Coconut oil
(C) Olive oil
(D) Pine oil
Answer : D

Question : Chemical method used in concentration of ore is also known as -
(A) bleaching
(B) leaching
(C) roasting
(D) calcination
Answer : B

Question : The smelting of iron in a blast furnace involves all the following processes except -
(A) combustion
(B) reduction
(C) slag formation
(D) sublimation
Answer : B

Question : Which of the following is purest form of iron ?
(A) Wrought iron
(B) Pig iron
(C) Steel
(D None of these
Answer : A

Question : Aluminium is not present in which of the following mineral .
(A) Cryolite
(B) Felspar
(C) Fluorspar
(D) Mica
Answer : C

Question : Match column A with column B and select the correct option -
Column A                      Column B
(Ore)                           (Nature of ore)
(a) Copper glance        (i) Sulphate ore
(b) Calamine               (ii) Halide ore
(c) Rock salt                (iii) Sulphide ore
(d) Epsom salt              (iv) Carbonate ore
(A) a(i), b(ii), c(iii), d(iv)
(C) a(iii), b(iv), c(ii), d(i)
(B) a(iv), b(ii), c(iii), d(i)
(D) a(iv), b(i), c(ii), d(iii)
Answer : C

Question : In the alumino-thermic process, aluminium acts as:
(A) An oxidizing agent
(B) A flux
(C) A reducing agent
(D) A solder
Answer : C

Question : Which of the following metal is found in native state ?
(A) Sodium
(B) Zinc
(C) Gold
(D) Iron
Answer : C

Question : Ore dressing for iron is done by -
(A) froth floatation process
(B) magnetic separation
(C) hand picking
(D) all of the above
Answer : B

Question : Copper is extracted from the ore copper pyrite by smelting in a blast furnace. The flux used and the slag formed are as given below :
(A) Flux CaO, Slag CaSiO₃
(B) Flux SiO₂, Slag CaSiO₃
(C) Flux FeO, Slag FeSiO₃
(D) Flux SiO₂, Slag FeSiO₃
Answer : D

Question : _______ is not present in gun metal .
(A) Cu
(B) Sn
(C) Zn
(D) Fe
Answer : D

Question : Baking soda is :
(A) Na₂CO₃
(B) Ca (OH)₂
(C) NaHCO₃
(D) NaCl
Answer : C

Question : Cl₂ acts as bleaching agent because in presence of moisture it produces :
(A) O₂
(B) Cl
(C) O
(D) HCl
Answer : B

Question : Molten sodium chloride conducts electricity due to the presence of
(A) free electrons
(B) free molecules
(C) atoms
(D) free ions
Answer : D

Question : The alloy used for the construction of bells is -
(A) tungsten steel
(B) nickel steel
(C) bell metal
(D) duralumin
Answer : C

Question : Sodium chloride is known as -
(A) Rock salt
(B) Common salt
(C) Table salt
(D) All
Answer : D

Assertion/Reason Type Question

Following Questions consist of two statements – Assertion (A) and Reason (R).
Answer these questions selecting the appropriate option given below:
A. Both A and R are true, and R is the correct explanation of A
B. Both A and R are true, and R is not the correct explanation of A
C. A is true, but R is false
D. A is False, but R is true

Question. Assertion (A) : Rusting of iron is a slow combustion
Reason (R) : Iron slowly reacts with oxygen and form iron oxide.
Answer : A

Question. Assertion (A) : MgCl₂, is a covalent compound
Reason (R) :MgCl2, is a good conductor of electricity in molten state.
Answer : D

Question. Assertion (A) : Aluminium is more reactive than iron. Its corrosion is less than that of iron.
Reason (R) : Aluminium is covered with a strong protective layer of oxide which protects the metal from further corrosion.
Answer : A

Question. Assertion (A) : The oxides of sulphur and phosphorus are acidic in nature.
Reason (R) : Metal oxides are basic in nature
Answer : B

Question. Assertion (A) : Gold occurs in native state.
Reason (R) : Gold is a reactive metal.
Answer : C

Case Study Based Questions

1. When a silvery grey powder of a solid (A) is mixed with a powder solid (B) no reaction occurs. But if the mixture is ignited and lighted using magnesium ribbon a reaction occurs with evolution of large amount of heat forming product (C) which settles down as liquid metal and the solid product(D) formed floats on the liquid (C) . (C) in solid form reacts with moisture to form rust. The amount of heat generated during the reaction is so high that the reaction is used in welding of electric conductors, joints in railway tracks. Based on this information, answer the following questions.

i. Identify A and C?
(a) A- Al and C- Fe
(b) A-Fe and C—Al
(c) A-Mg and C -Al
(d) A-Al and C -Cu
Answer : A

ii. Identify B and D which are oxides of
(a) B- Fe , D- Al
(b) B- Mg, D-Al
(c) B- Al , D- Cu
(d) B-Al , D –Fe
Answer : A

iii . Amphoteric oxides are
(a) metal oxides which do not react with acids but react with bases
(b) metal oxides which reacts with both acids as well as bases
(c) metal oxides which reacts with acids but do not react with bases
D metal oxides which shows no reaction with either acids or bases
Answer : B

iv. Which of the following is amphoteric in nature?
(a) both aluminium oxide and zinc oxide
(b) Only Zinc oxide
(c) Only Aluminium oxide
(d) Neither of them
Answer : A

Questions with Answers:

Question: Carbon can reduce copper oxide to copper but not calcium oxide to calcium. Why?
Answer : Carbon is a strong reducing agent so it can reduce copper oxide but calcium is much more reactive than copper and has greater affinity for oxygen than carbon has. So it cannot reduce calcium oxide to calcium. 

Question. A yellow coloured powder `X` is soluble in carbon disulfide. It burns with a blue flame forming suffocating smelling gas which turns moist blue litmus red. Identify `X` and gives chemical reaction. Identify it is metal or nonmetal. 
Answer :` X` is sulphur S + O2 -> SO2 It is non metal. 

Question. Nikita took Zn, Al, Cu, Fe, Mg, Na metals & put each metal in cold water and then hot water. She reacted the metal with steam
(i) Name the metal which reacts with cold water.
(ii) Which of the above metals react with steam?
(iii) Name the metal which reacts with hot water.
(iv) Arrange these metals in order of increasing reactivity.
Answer : 
(i) Na
(ii) Al, Zn, Fe
(iii) Mg
(iv) Na>Mg> Al > Zn > Fe > Cu 

Question. A student was given Mg, Zn, Fe, and Cu metals. He put each of them in dil HCl contained in different test tubes. Identify which of  hem
(i) will not displace H2 from dil HCl
(ii) forms a pale green substance
(iii) will give H2 with 5% HNO3
(iv) will be displaced from its salt solution by all other metals.
Answer : 
(i) Cu (ii) Fe (iii) Cu (iv) Cu 

Question. A metal acts as a good reducing agent. It reduces Fe2O_3, and MnO₂. The reaction with Fe₂O₃ is used for welding broken railway tracks. Identify the metal and write all the chemical reactions.

Question. A yellow coloured powder `X` is soluble in carbon disulfide. It burns with a blue flame forming suffocating smelling gas which turns moist blue litmus red. Identify `X` and gives chemical reaction. Identify it is metal or nonmetal.

Question. An element reacts with oxygen to form an oxide which dissolves in dilutehydrochloric acid. The oxide formed also turns a solution of red litmus blue. Is the element a metal or non-metal? Explain with the help of a suitable example.
Answer : 
It is metal
4Na(s) + O₂  →  2Na ₂O (s)
Na ₂O (s) + H₂O(l) → 2naOH(aq)
Na ₂O (s) + 2HCl (dil)  →  2NaCl (aq) +H₂O (l)

Question.

Answer : 
(i) Yes the bulb glows, this indicates that metal is a good conductor of electricity
(iii) Rubber like substance is a bad conductor of electricity

Question. Royal water is prepared by mixing two acids `A` and `B`. It can dissolve gold and platinium. It is highly corrosive and fuming liquid. Identify `A` and `B`. What is the ratio in which `A` and `B` are mixed.
Answer : 
3HCl + HNO₃

Question.. Four metals A, B, C and D are, in turn, added to the following solutions one by one. The observations made are tabulatd below: Answer the following questions based on above information.

(i) Which is the most active metal and why?
(ii) What would be observed if B is added to a solution of copper (II) sulphate and Why?
(iii) Arrange the metals A, B, C and D in order of increasing reactivity.
(iv) Container of which metal can be used to store both zinc sulphate solution and silver nitrate solution.
(v) Which of the above solutions can be easily stored in a container made up of any of these metals?
Answer : 
(i) B
(ii) Displacement reaction. Because B is more reactive than Cu.
(iii) B.>A.>C.>D
(iv) D 
(v) ZnSO₄

Metals And Non Metals