100525 + Interview Questions in GENERAL QA IN GENERAL AWARENESS

1.	How did the Non-Cooperation Movement spread to the countryside and drew into its fold the struggles of peasants and tribal communities? Elaborate.
Answer» (i) Struggle of Peasants in Awadh and formation of Kisan Sabhas (a) In Awadh, the peasant movement was led by Baba Ramchandra-a sanyasi who had earlier worked in Fiji as an indentured labourer. (b) The movement here was against talukdars and landlords who demanded high rents from the peasants. (c) Peasants had to do begar and work at landlords' farms without any payment. (d) The peasant movement demanded reduction of revenue, abolition of begar and social boycott of oppressive landlords. (e) In many places Nai-Dhobhi bandhs were organised to deprive landlords of the services of even washermen and barbers. (f) Jawaharlal Nehru began talking to the villagers and formed 'Oudh Kisan Sabha'. (g) Within a month, over 300 branches had been set up in the villages around the region. (h) As the movement spread in 1921, the houses of talukdars and merchants were attacked, bazaars were looted and grain hoards were taken over. (ii) Struggle of the Tribals in the Gudem Hills of Andhra Pradesh (a) In the Gudem Hills of Andhra Pradesh, tribals started a movement under the leadership of Alluri Sitaram Raju. (b) Tribals wanted to get back their traditional rights over forests. (c) Alluri Sitaram Raju led the movement of the tribal people in the Gudem hills of Andhra Pradesh. (d) Many people considered him as an incarnation of God. They believed that he had many special powers. (e) He supported Gandhiji and asked his followers to wear khadi and stop drinking. But, he organised an armed struggle against the British.

1.

How did the Non-Cooperation Movement spread to the countryside and drew into its fold the struggles of peasants and tribal communities? Elaborate.

Answer»

(i) Struggle of Peasants in Awadh and formation of Kisan Sabhas

(a) In Awadh, the peasant movement was led by Baba Ramchandra-a sanyasi who had earlier worked in Fiji as an indentured labourer.

(b) The movement here was against talukdars and landlords who demanded high rents from the peasants.

(c) Peasants had to do begar and work at landlords' farms without any payment.

(d) The peasant movement demanded reduction of revenue, abolition of begar and social boycott of oppressive landlords.

(e) In many places Nai-Dhobhi bandhs were organised to deprive landlords of the services of even washermen and barbers.

(f) Jawaharlal Nehru began talking to the villagers and formed 'Oudh Kisan Sabha'.

(g) Within a month, over 300 branches had been set up in the villages around the region.

(h) As the movement spread in 1921, the houses of talukdars and merchants were attacked, bazaars were looted and grain hoards were taken over.

(ii) Struggle of the Tribals in the Gudem Hills of Andhra Pradesh

(a) In the Gudem Hills of Andhra Pradesh, tribals started a movement under the leadership of Alluri Sitaram Raju.

(b) Tribals wanted to get back their traditional rights over forests.

(c) Alluri Sitaram Raju led the movement of the tribal people in the Gudem hills of Andhra Pradesh.

(d) Many people considered him as an incarnation of God. They believed that he had many special powers.

(e) He supported Gandhiji and asked his followers to wear khadi and stop drinking. But, he organised an armed struggle against the British.

Discussion

2.	Assertion : Zinc is used for the recovery of silver from the complex `[Ag(CN)_(2)]^(-)` Reason : Zinc is more electropositive than silver and is a better reducing agent.A. Both assertion and reason are correct statements, and reason is the correct explanation of the assertion.B. Both assertion and reason are correct statements, but reason is not the correct explanation of the assertion.C. Assertion is correct, but reason is wrong statement.D. Assertion is wrong, but reason is correct statement.
Answer» Correct Answer - A Reason is the correct explanation for Assertion.

Discussion

3.	Assertion : van Arkel method is used for refining of Zinc. Reason : In this method impure is evaporated to obtain the pure metal as distillate .A. If both assertion and reason are true and reason is the correct explanation of assertion .B. if both assertion and reason are true but reason is not the correct explanation of assertionC. If assertion is true but reason is falseD. If both assertion and reason are false.
Answer» Correct Answer - D van Arkel method is used for refining of zirconium or titanium. In this method crude metal is heated in an evacuated vessel with iodine . `underset("Impure")(Zr) + 2I_(2) overset(Delta)to ZrI_(4)` The metal iodide is decomposed on tungsten filament, and pure metal is deposited on the filament . `ZrI_(4) overset(Delta) to underset("Pure")(Zr) +2I_(2)`

Discussion

4.	Assertion : Chromatography in general involves a mobile (a gas, a liquid or a supercritical fluid) and a stationary phase (like `Al_(2)O_(3)` column). Reason : A component which is less soluble in stationary phase takes longer time to travel through it than the component which is more soluble in stationary phase.A. If both assertion and reason are true and reason is the correct explanation of assertion .B. if both assertion and reason are true but reason is not the correct explanation of assertionC. If assertion is true but reason is falseD. If both assertion and reason are false.
Answer» Correct Answer - C A component which is quite soluble in the sationary phase, takes longer time to travel through it than a component which is not very soluble in the stationary phase but very soluble in the mobile phase.

Discussion

5.	In van Arkel method, if `I_(2)` is introducted at `1800K` anode impure zironium metal, the product will be:A. iodide of the nmetalB. pure metalC. inpuritiesreact with iodineD. none of these
Answer» Correct Answer - D `Zr("impure")+2I_(2)overset(lt1800K)rarrZrI_(4)`, `ZrI_(4)overset(gt1800K)rarrZr(pure) +2I_(2)` and hence over `1800K` pratically on reaction can take place between `Zr` and `I_(2)`. Therefore, `(d)` options is correct.

Discussion

6.	Bauxite ore is concentrated by
Answer» Correct Answer - `(2)` Bauxite ore is `Al_(2) O_(3) .2H_(2)O`.

Discussion

7.	During reduction of `ZnO` to `Zn, C` is more efficient than `CO`. The standard free energy of formation of `CO_(2)` from `CO` is always higher than that of `ZnO`.A. If both (A) and ( R) are correct and ( R) is the correct explanation of (A).B. If both (A) and ( R) are correct, but ( R) is not the correct explanation of (A).C. If (A) is correct, but ( R) is incorrect.D. If (A) is incorrect, but ( R) is correct.
Answer» Correct Answer - B `Delta_(f)G^(Ө)` of `CO_(2)` from `CO` is higher than `Delta_(f) G^(Ө)` of `ZnO`, hence `CO` cannot be used to reduce `ZnO` to `Zn`.

Discussion

8.	Assertion: `A1` is obtained by high temperature reduction of alumina with carbon. Reason: Alumina reacts with carbon to form `A1_(2)O_(3)` which does not decompose.A. If both assertion and reason are true and the reason is the correct explanation of the assertion.B. If both assertion and reason are true but reason is not the correct explanation of the assertion.C. If assertion is true but reason is false.D. If assertion is false but reason is true.
Answer» Correct Answer - D Correct Assertion: `A1` is extracted by high temperature electrolytic reduction of `A1_(2)O_(3)` to which fluorspar and cryolite have been added.

Discussion

9.	Assertion: Carbonate and hydroxide orea re concentrated by froth floatation process. Reason: In froth floataiton process, pine is used because it preferentially wets the ore particles.A. If both assertion and reason are true and the reason is the correct explanation of the assertion.B. If both assertion and reason are true but reason is not the correct explanation of the assertion.C. If assertion is true but reason is false.D. If assertion is false but reason is true.
Answer» Correct Answer - D Correct Assertion: Sulphide ores are concentrated by froth floatation process.

Discussion

10.	Pine oil is generally added in the froth floatation process. Explain.
Answer» In the froth flotation process, sulphide ore is to be separated from gangue or earthy impurities. The impure ore is mixed with water and pine oil in a tank and steam is passed through it. Now, gangue particles are wetted by water while the ore by oil. With the help of steam, the sulphide ore rises in the form of a foam while the gangue impurities settle at the bottom of the container.

Discussion

11.	Roasting is a process in which the ore (mostly sulphide) is heated strongly in the presence of excess of air. The heating should be done at a temperature below the melting point of the ore. Sometimes roasting may not bring about complete oxidation : `2CuFeS_(2) + 4O_(2) rarr A + 2FeO + 3SO_(2)` Find the `A` :A. `Cu_(2) O`B. `CuO`C. `Cu_(2) O`D. `CuS`
Answer» Correct Answer - C `2CuFeS_(2) + 4O_(2) rarr underset((A)) (Cu_(2)S + 2FeO + 3SO_(2)` Hence, `(A)` is `Cu_(2) S`.

Discussion

12.	The normal level of glucose in blood a. 80 – 130 mg/100 ml b. 70 – 110 mg/100 ml c. 9-11 mg/100 ml d. 60 – 100 mg/100 ml
Answer» Correct option: b. 70-110 mg/100 ml

Discussion

13.	This bag isn’t ______ it looks. A) as lightly as B) lighter C) as light as D) the lightest
Answer» Correct option is C) as light as

Discussion

14.	The main reaction occuring in blast furnace during the extraction of iron form haematite isA. `Fe_(2)O_(3) +3Crarr2Fe+3CO`B. `CO_(2)+C`C. `FeO +SiO_(2)rarrFeSiO_(3)`D. `CaO +SiO_(2)rarr CaSiO_(3)`
Answer» Correct Answer - D In slag formation zone impurity is combined with flux to from slag `CaO +SiO_(2)rarr CaSiO_(3)`

Discussion

15.	Chromatography is used for the purification ofA. very reactiveB. available in minute quantitiesC. present in abundanceD. highly electropositve
Answer» Correct Answer - B Chromatography is useful for purification of the elements which are available in minute quantities and the impurities are not very different in chemical properities from the element to be purified.

Discussion

16.	Mark the correct statements. (i) Mercury can be refined by the process of distillation. (ii) In poling, the molten impure metal is stirred with green poles of wood. (iii) In electrolytic refining of metals , impure metal is made as cathode and a thin strip of pure metal is made as anode.A. (i) and (ii)B. (i) and (iii)C. (ii) and (iii)D. (i), (ii) and (iii)
Answer» Correct Answer - A In electrolytic refining of metals, impure metal is made as anode and a thin strip of pure metal is made as cathode.

Discussion

17.	Thermite is a mixture of `:`A. Fe powder and ` Al_2O_3`B. Al powder and ` Fe_2O_3`C. Cu powder and ` Fe_2 O_3`D. Zn powder and `Cr_2O_3`
Answer» Correct Answer - B Thermite is a mixture of Al and `Fe_2O_3` in 1:3 ratio.

Discussion

18.	Questions given below are based on the given diagram for extractive metallurgy. (iii) The make the following process spontaneous, temperature should be : `ZnO + C rarr Zn + CO`.A. ` lt 1000^@ C`B. `gt 1100^@ C`C. `lt 500^@ C`D. `gt 500^@ C " but" lt 1000^@ C`
Answer» Correct Answer - D To make the reaction `ZnO + C rarr Zn + CO` to proceed in forward direction, temperature should be greater than `1100^@C`.

Discussion

19.	Questions given below are based on the given diagram for extractive metallurgy. (ii) At this temperature `Delta_(f) G^(Ө)` of the reaction is `ZnO + C rarr Zn + CO`. .A. `-ve`B. ` +ve`C. ZeroD. Nothing can be said
Answer» Correct Answer - C At `~ 1000^@ C`, since `Zn` and `C` have equal affinity for `O_(2),Delta_(f) G^(Ө)` of the reaction is zero. `ZnO + C rarr Zn + CO`.

Discussion

20.	Questions given below are based on the given diagram for extractive metallurgy. (i) At what approximate temperature, zinc and carbon have equal affinity for oxygen ?A. `1000^@ C`B. `1500^@ C`C. `500^@ C`D. `1200^@ C`
Answer» Correct Answer - A At `~ 1000^@ C`, lines `(C,CO)` and `(Zn,ZnO)` intersect , at this temperature zinc and carbon have equal affinity for oxygen.

Discussion

21.	How many metals are commercially purified by electrolysis method from the given metals ? `Na, Al, Pb, Ni`.
Answer» Correct Answer - `(2)` `Al` and `Pb`

Discussion

22.	Questions given below are based on the given diagram for extractive metallurgy. (iv) At `1100^@C`, which reaction is spontaneous to a maximum extent ?A. `MgO + C rarr Mg + CO`B. `ZnO + C rarr Zn + CO`C. `MgO + Zn rarr Mg + ZnO`D. `ZnO + Mg rarr MgO + Zn`
Answer» Correct Answer - D At `1100^@C, Delta_(r)G^(Ө)` for the reaction `ZnO + Mg rarr MgO + Zn` has highest negative value, hence this reaction will be spontaneous to a maximum.

Discussion

23.	Find the number of following reactions which are involved in roasting process : (i) `S_(8) + 8 O_(2) overset (Delta)rarr 8SO_(2) uarr` (ii) `P_(4) + 5O_(2) overset (Delta) rarr P_(4) O_(10) uarr` (iii) `4 As + 3O_(2) overset (Delta) rarr 2 As_(2) O_(3) uarr` (iv) `2ZnS + 3 O overset (Delta) rarr 2 ZnO + 2SO_(2) uarr` (v) `ZnCO_(3) overset (Delta) rarr 4 ZnO + CO_(2) uarr`.
Answer» Correct Answer - `(4)` Roasting is heating the ore in presence of `O_(2)`. Reactions (i),(ii),(iii) and (iv) can be termed roasting.

Discussion

24.	Assertion: Extraction of zinc from sphalerite ore involes the roasting followed by reduction with coke. Reason: Zinc can be extracted by hydrometallurgy.A. If both assertion and reason are true and the reason is the correct explanation of the assertion.B. If both assertion and reason are true but reason is not the correct explanation of the assertion.C. If assertion is true but reason is false.D. If assertion is false but reason is true.
Answer» Correct Answer - C Assertion. Sphalerite is `ZNS`, `2ZnS +3O_(2)rarr 2ZnO +2SO_(2)`, `ZnO + C rarrZn +CO`. Reason: Zinc is highly reactive metal, it cannot be displace form a solution of `ZnSO_(4)` so easily. Thus reason is incorrect.

Discussion

25.	`A overset("Calcination")rarr CaO + MgO + underset("Colourless gas")((B))` When the colourless gas `(B)` is passed through lime water, initially a milky solution is obtained and on excess passage of gas `(B)` through the lime water, milkiness disappears. `(B)` is.A. `CO_(2)`B. `SO_(2)`C. `CO`D. `SO_(3)`
Answer» Correct Answer - A Since on calcination, i.e., heating the ore `(A)` is limited supply of `O_(2)`, both `CaO` and `MgO` are formed along with a colourless gas `(B). (A)` is `CaCO_(3).MgCO_(3).(A)` is known as dolomite. `CaCO_(3).MgCO_(3) overset("Calcination")rarr CaO + MgO + underset((B))(2CO_(2))` `CO_(2) + underset("Lime water")(Ca(OH)_(2))rarr underset("Milkiness") (CaCO_(3))+ H_(2) O` `CaCO_(3) +H_(2) O + CO_(2) rarr underset("Milkiness disappears") (Ca(HCO_(3))_(2))` On passing `CO_(2)` through lime water `[Ca(OH)_(2)]` solution, initially lime water turns milky due to formation of `CaCo_(3)`, which is insoluble in water. On excess passage of `CO_(2)` gas through lime water, milkiness disppears due to formation of `Ca(HCO_(3))_(2)`. Hence. (ii) `B` is `CO_(2)`.

Discussion

26.	`A overset("Calcination")rarr CaO + MgO + underset("Colourless gas")((B))` When the colourless gas `(B)` is passed through lime water, initially a milky solution is obtained and on excess passage of gas `(B)` through the lime water, milkiness disappears. `(A)` is :A. `CaCO_(3)`B. `MgCO_(3)`C. `CaCO_(3).MgCO_(3)`D. `CaSO_(4).MgCO_(3)`
Answer» Correct Answer - C Since on calcination, i.e., heating the ore `(A)` is limited supply of `O_(2)`, both `CaO` and `MgO` are formed along with a colourless gas `(B). (A)` is `CaCO_(3).MgCO_(3).(A)` is known as dolomite. `CaCO_(3).MgCO_(3) overset("Calcination")rarr CaO + MgO + underset((B))(2CO_(2))` `CO_(2) + underset("Lime water")(Ca(OH)_(2))rarr underset("Milkiness") (CaCO_(3))+ H_(2) O` `CaCO_(3) +H_(2) O + CO_(2) rarr underset("Milkiness disappears") (Ca(HCO_(3))_(2))` On passing `CO_(2)` through lime water `[Ca(OH)_(2)]` solution, initially lime water turns milky due to formation of `CaCo_(3)`, which is insoluble in water. On excess passage of `CO_(2)` gas through lime water, milkiness disppears due to formation of `Ca(HCO_(3))_(2)`. Hence. (i) `A` is `CaSO_(3). MgCO_(3)`.

Discussion

27.	Find the number of reaction from the given reaction which can show calcination process : (i) `CaCO_(3).MgCO_(3) overset (Delta) rarr CaO + MgO + CO_(2)` (ii) `CuCO_(3).Cu(OH)_(2) overset (Delta) rarr 2CuO + H_(2)O + CO_(2)` (iii) `Al_(2)O_(3). 2H_(2)O overset (Delta) rarr Al_(2)O_(3) + 2H_(2)O` (iv) `2Cu_(2)S + 3O_(2) overset (Delta) rarr 2Cu_(2) O + 2SO_(2)`.
Answer» Correct Answer - `(3)` Calcination is heating the ore strongly in absence of `O_(2)` or air. Reactions (i),(ii), and (iii) are calcination reactions.

Discussion

28.	`A overset("Calcination")rarr CaO + MgO + underset("Colourless gas")((B))` When the colourless gas `(B)` is passed through lime water, initially a milky solution is obtained and on excess passage of gas `(B)` through the lime water, milkiness disappears. Name of the product `(A)` is :A. DolomiteB. LimenstoneC. MagnesiteD. Malachite
Answer» Correct Answer - A Since on calcination, i.e., heating the ore `(A)` is limited supply of `O_(2)`, both `CaO` and `MgO` are formed along with a colourless gas `(B). (A)` is `CaCO_(3).MgCO_(3).(A)` is known as dolomite. `CaCO_(3).MgCO_(3) overset("Calcination")rarr CaO + MgO + underset((B))(2CO_(2))` `CO_(2) + underset("Lime water")(Ca(OH)_(2))rarr underset("Milkiness") (CaCO_(3))+ H_(2) O` `CaCO_(3) +H_(2) O + CO_(2) rarr underset("Milkiness disappears") (Ca(HCO_(3))_(2))` On passing `CO_(2)` through lime water `[Ca(OH)_(2)]` solution, initially lime water turns milky due to formation of `CaCo_(3)`, which is insoluble in water. On excess passage of `CO_(2)` gas through lime water, milkiness disppears due to formation of `Ca(HCO_(3))_(2)`. Hence. (iii) `CaCO_(3) . MgCo_(3)` is known as dolomite.

Discussion

29.	Copper and silver lie below hydrogen in electrochemical series and yet they are found in the combined state as sulphides in nature. Comment.
Answer» Copper and silver are found in the combined states as sulphides as `Cu^(2+)` and `Ag^(oplus)` ions have high polarising power and their sulphides are more stable than metals.

Discussion

30.	Statement-1:Extraction of gold from its native ore involves leaching the metal ore with dilute solution of NaCN in presence of air. Statement-2:This is an oxidation reaction and leads to the formation of a soluble complex.A. Statement-1 is True, Statement-2 is True, Statement-2 is a correct explanation for Statement-1B. Statement-1 is True, Statement-2 is True, Statement-2 is NOT a correct explanation for Statement-1C. Statement-1 is True, Statement-2 is False.D. Statement-1 is False, Statement-2 is True.
Answer» Correct Answer - A `Au(s)oversetO_2toAu^+(aq.)` `Au^+ + 2CN^(-) (aq.) to [Au(CN)_2]^(-)` soluble complex.

Discussion

31.	From the Ellingham graph between Gibbs energy and temperature , out of C and CO which is a better reducing agent for ZnO ?A. CarbonB. COC. Both of theseD. None of these
Answer» Correct Answer - A The free energy of formation `(DeltaG^(@))` of CO from C becomes lower at temperature above 1180 K whereas that of `CO_(2)` from C becomes lower aboveb 1270 K than `DeltaG^(@)` of ZnO. However , `DeltaG^(@)` of `CO_(2)` from CO is always higher than that of ZnO. Hence, C can reduce ZnO to Zn but not CO.

Discussion

32.	Green coloured ore among the folowing isA. `Cu_(2)O`B. `CuFeS_(2)`C. `CuCO_(3).Cu(OH)_(2)`D. `2CuCO_(3).Cu(OH)_(2)`
Answer» Correct Answer - C `CuCO_(3).Cu(OH)_(2)` is green coloured compound.

Discussion

33.	How is cas iron different from pig iron ?A. cast iron is purest form of iron while pig iron is impureB. cast iron has lower carbon content (3%) as compared to pig iron (4%) and is extremely hard and brittle.C. pig iron contains many impurities like S, P, Si and Mn while cast iron does not contain any impurity and can be casted into any shapeD. Cast iron is soft and malleable while pig iron heating it with
Answer» Correct Answer - B Pig iron contains about 4% C and many other impurities like S, P SI and Mn. Cast iron is made by melting pig iron with scrap iron and coke. It has slightly lower carbon content (3%) and is extremely hard and brittle.

Discussion

34.	An ore on heating in air produces sulphur dioxide. Which process would you suggest for its concentration Describe briefly any two steps involved in the conversion of this concentrated ore into related metal
Answer» The ore on heating produces sulphur dioxide gas so it is a sulphide ore. The method used for its concentration is "froth floatation process". After concentration of the ore following two steps would be followed to convert it into metal. (i) Roasting: The sulphide ore is converted into its oxide by heating it in the presence of air. MS + O₂ -------> MO + SO₂ ↑ (ii) Reduction of metal oxide to metal: The oxide formed by roasting is then reduced to metal by using a suitable reducing agent like carbon (coke). MO+C------>M+CO

Discussion

35.	In blast furnace, iron oxide is reduced byA. SilicaB. `CO`C. CarbonD. Limestone
Answer» Correct Answer - B `Fe_(2)O_(3) +3CO rarr 2Fe +3CO_(2)`

Discussion

36.	The major role of flourspar, `CaF_(2)` which is added in small amount in the electrolytic reduction of `Al_(2)O_(3)` dissolved on fused cryolite in fused cryolite isA. as a catalystB. to lower the temperature of the melt and improve the conductivity of cellC. to decrease the rate of oxidatiom of carbon at the anodeD. to decrease the raet of oxidaiton of carbon at the cathode
Answer» Correct Answer - B `CaF_(2)` and `Na_(3)A1F_(6)` are added to decrease the melting point of electrolyte and increase the conductivity if cell.

Discussion

37.	Differentiate between “minerals” and “ores”.
Answer» Minerals are naturally occurring chemical substances containing metals. They are found in the Earth’s crust and are obtained by mining. Ores are rocks and minerals viable to be used as a source of metal. For example, there are many minerals containing zinc, but zinc cannot be extracted profitably (conveniently and economically) from all these minerals. Zinc can be obtained from zinc blende (ZnS), calamine (ZnCO₃), Zincite (ZnO) etc. Thus, these minerals are called ores of zinc.

Discussion

38.	Write the balanced chemical equations for the following reactions.i) Calcium hydroxide + Carbon dioxide → Calcium carbonate + waterii) Zinc + Silver nitrate → Zinc nitrate + silveriii) Aluminium + Copper chloride → Aluminium chloride + Copper
Answer» i) Ca(OH)_2(aq) + CO_2(g) → CaCO_3(s) + H₂O_(l) ii) Zn_(s) + 2AgNO₃ → Zn(NO₃)_2(aq) + 2Ag_(s) iii) 2Al_(s) + 3CuCl_2(aq) → 2AlCl_3(aq) + 3Cu

38.

Write the balanced chemical equations for the following reactions.i) Calcium hydroxide + Carbon dioxide → Calcium carbonate + waterii) Zinc + Silver nitrate → Zinc nitrate + silveriii) Aluminium + Copper chloride → Aluminium chloride + Copper

Answer»

i) Ca(OH)_2(aq) + CO_2(g) → CaCO_3(s) + H₂O_(l)

ii) Zn_(s) + 2AgNO₃ → Zn(NO₃)_2(aq) + 2Ag_(s)

iii) 2Al_(s) + 3CuCl_2(aq) → 2AlCl_3(aq) + 3Cu

Discussion

39.	List the physical properties of metals.
Answer» Physical properties of metals are: (i) Metals are usually hard. (ii) They are Sonorous. (iii) They are lustrus (iv) Metals exhibit malleability and ductility (v) They exhibit high tensile strength and have high densities.

39.

List the physical properties of metals.

Answer»

Physical properties of metals are:

(i) Metals are usually hard.

(ii) They are Sonorous.

(iii) They are lustrus

(iv) Metals exhibit malleability and ductility

(v) They exhibit high tensile strength and have high densities.

Discussion

40.	How does growing embryo get nutrition from the mother’s blood?
Answer» The embryo gets nutrition from the mother’s blood with the help of a special tissue called placenta. This is a disc which is embedded in the uterine wall and transfer glucose and oxygen from the mother to the embryo.

Discussion

41.	How is ‘cast iron’ different from ‘pig iron”?
Answer» The iron obtained from blast furnaces is known as pig iron. It contains around 4% carbon and many impurities such as S, P, Si, Mn in smaller amounts. Cast iron is obtained by melting pig iron and coke using a hot air blast. It contains a lower amount of carbon (3%) than pig iron. Unlike pig iron, cast iron is extremely hard and brittle.

Discussion

42.	'M' is an element which is out of Cu, Fe, Al, Na. It shows the following properties:(i) One of its ore is rich in M2O3.(ii) M2Os is not affected bY water.(iii) It corrodes easily.(iv) It forms two chlorides MCl2 and MCl3 identify 'M'
Answer» As the metal 'M' forms oxide M₂O₃ it is trivalent. Out of the metals listed, only Fe and Al are trivalent. M₂O₃ is not affected by water, so 'M' can be out of Fe or Al. Fe and Al both corrode easily. Out of Al and Fe, only Fe can form divalent chloride, so the element 'M' is Fe.

42.

'M' is an element which is out of Cu, Fe, Al, Na. It shows the following properties:(i) One of its ore is rich in M2O3.(ii) M2Os is not affected bY water.(iii) It corrodes easily.(iv) It forms two chlorides MCl2 and MCl3 identify 'M'

Answer»

As the metal 'M' forms oxide M₂O₃ it is trivalent. Out of the metals listed, only Fe and Al are trivalent.
M₂O₃ is not affected by water, so 'M' can be out of Fe or Al.

Fe and Al both corrode easily.

Out of Al and Fe, only Fe can form divalent chloride, so the element 'M' is Fe.

Discussion

43.	Electromagnetic waves with wavelength λ is used to detect leakage of oil in underground pipelines. Name the part of electromagnetic spectrum to which this radiation belong. Write it’s one more application.
Answer» λ : x- rays x- ray is used to detect a fractures in bones.

Discussion

44.	Thymus is present near- (a) Heart (b) Kidney (c) Liver (d) Testis
Answer» Thymus is present near Heart.

Discussion

45.	Mendel worked on- (a) Garden pea (b) Chick pea (c) Pigeon pea (d) Grass pea
Answer» Mendel worked on Garden pea.

Discussion

46.	What are the uses of nitrobenzene?
Answer» 1. Nitro benzene is used to produce lubricating oils in motors and machinery. 2. It is used in the manufacture of dyes, drugs, pesticides, synthelic rubber, aniline and explosives like TNT, TNB.

46.

What are the uses of nitrobenzene?

Answer»

1. Nitro benzene is used to produce lubricating oils in motors and machinery.

2. It is used in the manufacture of dyes, drugs, pesticides, synthelic rubber, aniline and explosives like TNT, TNB.

Discussion

47.	Walking fern isA. GinkgoB. GnetumC. AdiantumD. Ephedra
Answer» Correct Answer - C Walking fern is Adiantum.

Discussion

48.	Megasporophyll of cycas is equivalent to the angiospermicA. StamenB. Embryo sacC. CarpelD. Nucellus
Answer» Correct Answer - C Megasporophyll of cycas is equivalent to the angiospermic carpel.

Discussion

49.	Name the hormones of adrenal gland and mention their functions.
Answer» Adrenaline: Stress hormone. Nor-adrenalinc: Stress hormone. Corticoids: Carbohydrate metabolism. Gluco-corticoids: Gluconeogenesis, lipolysis and proteolysis. Aldosterone: Reabsorption of Na⁺ , Water, K⁺ , Phosphate ions.

Discussion

50.	The absorption of ions or minerals from the soil by roots is
Answer» The correct answer is mostly by active transport In plants, the entrance portal for mineral uptake is usually through the roots. Some mineral ions diffuse in-between the cells. In contrast to water, some minerals are actively taken up by plant cells. Mineral nutrient concentration in roots maybe 10,000 times more than in surrounding soil.

50.

The absorption of ions or minerals from the soil by roots is

Answer»

The correct answer is mostly by active transport

In plants, the entrance portal for mineral uptake is usually through the roots. Some mineral ions diffuse in-between the cells.
In contrast to water, some minerals are actively taken up by plant cells.
Mineral nutrient concentration in roots maybe 10,000 times more than in surrounding soil.

Discussion

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