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InterviewSolution
This section includes InterviewSolutions, each offering curated multiple-choice questions to sharpen your knowledge and support exam preparation. Choose a topic below to get started.
| 8401. |
A pure dominant pea plant producing round - yellow seeds is crossed with pure recessive pea plant producing wrinkled - green seeds, The numbers of plants bearing round - green seeds in the F_(1) generation of Mendel's experiment is |
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Answer» 0 |
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| 8402. |
A proton is identical to |
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Answer» the nucleus of HELIUM |
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| 8403. |
A process which can take place either of its own or under some initiation is known as…… |
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| 8404. |
(i) Predict which of the following elements will form cation and will form anions ? (i) Na, (ii) Al, (iii) Cl, (iv) O. (ii) Name two elements that are inert in nature. |
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Answer» Solution :a) Na and Al FORM cations since they are METALS, and CL and O form anions since they are non-metals. B) Helium (He) and ARGON (Ar). |
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| 8405. |
A polar compound is insoluble in ................... solvent. |
| Answer» SOLUTION :non-polar | |
| 8406. |
A piece of sodium metal when added to absolute ethanol forms ______ and______ gas |
| Answer» SOLUTION :SODIUM ETHOXIDE , HYDROGEN | |
| 8407. |
A piece of granulated zinc was dropped into copper sulphate solution. After some time the colour of the solution changed from: |
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Answer» light GREEN to blue |
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| 8408. |
A pH-2 solution is more acidic than one with pH 6 by a factor of |
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Answer» 4000 pH = 6 has `(H^+) = 10^(-6) M` Solution with pH = 2 is 10000 more ACIDIC than solution with pH = 6 |
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| 8409. |
A person needs a lens of power +3D for correcting his near vision and -3D for correcting his distant vision. Calculate the focal lengths of the lenses required to correct these defects. |
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Answer» <P> Solution :Power of lens used for correction of NEAR vision, `P_(1)= +3D``THEREFORE` Its focal length `f_(1)=(1)/(P_(1))=(1)/(3)m=0.33m or +33.3cm` Power of lens used for correction of distant vision, `P_(2)= -3D` `therefore ` Its focal length `f_(2)=(1)/(P_(2))= -(1)/(3)m= -0.33m or -33.3cm` |
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| 8410. |
A person is suffering from both myopia and hypermetropia. (i) What kind of lenses can correct this effect? (ii) How are these lenses prepared? |
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Answer» SOLUTION :(i) The person should use bifocal lenses. (II) A bifocal lens is a combination of CONCAVE and another convex lens. Usually upper PORTION consists of a concave lens and facilitates distant vision. The lower part is a convex lens and facilitates near vision. |
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| 8411. |
A particular solution contains molecules and ions of the solute. Therefore, it is a:(a) weak acid(b) strong acid(c) strong base(d) salt solution |
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Answer» WEAK acid |
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| 8412. |
A particular compound contains only nitrogen and hydrogen. The percentage of nitrogen in The compound is 87.5%. Further, 96 g of the compound contains 18 xx 10^(23) molecular of thesubstance. Findout the molecular formula of the compound. |
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Answer» Solution :Number of MOLES of the GIVEN substance `=(18 xx 10^(23))/(6 xx 10^(23)) = 3` Weight of compound = 96 Gram molecular mass ofthe compound = `96/3 = 32 `g ` % " of " N_(2) = 87.5%` Number ofnitrogen atomsin 1 molecule of the compound = `(87.5 xx 32)/(100 xx 14) = 2` Similarly number of hydrogen atom in 1 moleculeof the compound = `(12.5 xx 32)/(100 xx 2) = 4` Molecular formula is `N_(2)H_(4)` |
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| 8413. |
A part of the periodic table has been shown below: Answer the following questions on the basis of position of elements in the above table : (a) Which element is a noble gas? Give reason. (b) Which element is most electronegative ? Give reason. (c) Write the electronic configuration of B and E. |
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Answer» Solution :Element G is a noble gas, because it is present in group 18 and has ZERO VALENCY. (b) Element E is the most electronegative element due to its small SIZE and GREATER tendency to gain electrons. (c) Electronic configuration of .B. = 2, 8, 1 Electronic configuration of .E. = 2,7 |
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| 8414. |
A part of s-block in the modern periodic table is given here. The correct arrangement of these atoms in the increasing order of there atomic size is |
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Answer» NA, Mg, K |
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| 8415. |
(a) One mole of atoms of an element 'X' absorb 800 kJ of energy for the formation of unipositive ions. For the conversion of one mole of 'X' atoms into tripositive ione, 6800 kJ of energy is required. Second and third ionisation energies are in 2 : 3 ratio. Calculate the second and third ionisation energies. (b) First and second second ionisation energies of Be_(g) are 900 and 1750 kJ/ mol, respectively. Calculate approximate percentade of Be_((g))^(2+)ions, if 1 g of Be_((g)) absorbs 150 kJ of eneergy (Be atomic weight is 9 ). |
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Answer» Solution :(a) `x to x^(+) , 800 kJ//mol (IP_1) ltbegt x to x^(+3) , 6800 kJ` ` thereforeIP_(1) + IP_(2) +IP_(3) =6800kJ rArr IP_(2)+IP_(3)=6800-800=6000` ` x^(+) to x^(+2) IP_(2), x^(+2) to x^(+3) to IP_(3)` `because IP_(2): IP_(3) =2:3 rArr(IP_(2))/(IP_(3))=2/3` `rArr IP_(2)=2/3. IP_(3) or IP_(3)=(3IP_2)/2` `rArr IP_(2) + IP_(3) = 6000` `rArr IP_(2) + 3/2. IP_(2) = 6000 rArr 2 IP_(2)+2IP_(3) =6000xx2` `IP_(2) =6000/2 xx2 = 2400 kJ// mol, IP_(3) =6000/5xx3 = 3600 kJ//mol` (B) 1 mole (9g) of beryllium requires 900 kJ to dislodge the first electron. `therefore` 1 g " of Be requires" `=(1xx900)/9=100kJ` `therefore` "Differnce in the amount of energy absorbed " `=150 -100=50kJ` To dislodge the second electron from 1 mole of Beryllium ION, 1750 kJ is required. 50 kJ OS sufficient for `50/1750xx9=0.25=25%` percentage of `Be_((g))^(2+)` ions is 25%. |
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| 8416. |
(a) On which side of the periodic table will you find metals? (b) On which side of the periodic table will you find non metals? (c) What is the name of those elements which divide metals and non metals in the periodic table? |
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| 8417. |
Write the balanced chemical equation for the following reactions. Calcium hydroxide + Carbon dioxide to calcium carbonate + water. |
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Answer» Solution :To prevent the oxidation of oil and fat present in food items. nitrogen gas is flushed in food packets products formed due to oxidation of oil and fat have unpleasant smell and taste due to rancidity. FLUSHING food items containing .fat and oil with nitrogen PREVENTS rancidity. B) i) `Ca(OH)_(2(aq))+ CO_(2(g)) to CaCO_(3(s)) + H_2 O_((l))` ii) `Zn_((s)) - 2AgNO_3 to ZN(NO_3)_(2(aq)) + 2Ag_((s))` iii) `2Al_((s)) + 2CuCl_(2(aq)) to 2AlCl_(3(aq)) + 3Cu` |
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| 8418. |
A non-metal A is an important constituent of food and forms two oxides B and C. Oxide of B is toxic whereas C causes global warming. (a) Identify A, B and C. (b) To which group of Periodic Table does A belong ? |
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Answer» Solution :(a) The non-metal A is carbon. Carbon is a constituent of CARBOHYDRATES, PROTEINS and fats. B = Carbon monoxide (CO) C = Carbon dioxide `(CO_2)` CO is a POISONOUS GAS and `CO_2`causes GLOBAL warming. (b) 14th group. |
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| 8419. |
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. |
| Answer» SOLUTION : X = CARBONY = DiamondZ = GRAPHITE | |
| 8420. |
A non-metal X exists in two different forms Y and Z. Y is the hardest natural substance, where as Z is a good conductor of electricity. Identify X, Y and Z. |
| Answer» SOLUTION :X is carbon (non-metal). X EXISTS in the form of ALLOTROPES, Y is diamond and Z is Graphite. | |
| 8421. |
A nitrogen molecule is formed by sharing of two pairs of electrons. |
| Answer» SOLUTION :False - Three pairs of electrons are SHARED to FORM NITROGEN molecule | |
| 8422. |
A natural phenomenon that supports the experimental conclusion that atoms are divis ible is |
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Answer» allotropy |
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| 8423. |
Name the metal which reacts with a very dilute HNO_(3) to evolve hydrogen gas. |
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Answer» Solution :(a) Magnesium and Manganese (B) Formation loses twon ELECTRONS , and forms Magnesium ions to complete its octet. `MG rarr Mf^(2+) +2^( e )` oxygen GAINS that two electrons to becomes `o^(2-)` `Mg^(2+) +O_(2) rarr MGO` 
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| 8424. |
(a) Name three elements that have a single electron in their outermost shells. (b) Name two elements that have a two electrons in their outermost shells. (c)Name thre elements with completely filled outermost shells. |
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| 8425. |
(a) Name the type of chemicalreactionresponsible for causing rancidity and define the term rancidity. (b) Write two methods for preventing rancidity of food. |
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Answer» Solution :(a) When fats and oils are oxidised, the food becomes rancid i.e., their smell and taste changes. The type of chemical reaction is a oxidation . Definition : Rancidity is the PROCESS of SLOW oxidation of oil and FAT present in the food materialsresulting in the production of foul odour and taste in them . (b) Methods to prevent Rancidity : (i) Methods to prevent rancidity : (i) Refrigeration of cooking food at low temperatures . (II) Packing of food materials in air tight containers. |
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| 8426. |
a) Name the hormone secreted by an endocrine gland during emergency. b) Compare and contrast nervous and hormonal mechanism for control and co-ordination in animals ? |
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Answer» Solution : a) Adernalin hormone is secreted by the adrenal GLAND. It helps to regulate heartbeat, blood pressure, metabolism in the times of strees or emergency to COPE up with the situation. b) Nervous system : * It consists of nerve impules between PNS, CNS and brain * The axone and dendrite transmit through a coordinated effort. * The flow of information is RAPID and the response is quick * Nerve impulses are not specific in their action. * Effects are short level. Hormonal system * It consists of endocrine system which secrete HORMONES directly into blood. * The information is TRANSMITTED or transported through blood. * The information travels slowly and the response is slow. * Each bormone has specific action * It has prolonged effects. |
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| 8427. |
a] Name the element with atomic number 17. b]To which period does it belong? c]To which group does it belong? d]Write its electronic configuration. |
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Answer» Solution :a] Chlorine (CI). B] Since it has 3 electron shells, it belongs to the 3rd PERIOD. c] Since it has 7 valence ELECTRONS, it belongs to the 17th group. d] Its electronic configuration is 2, 8, 7. |
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| 8428. |
a) Name the gas released at anode during chlor - alkali process and mention the uses of this gas. b) Which gas is released when sodium carbonate reacts with hydrochloric acid? How do you test this gas? Write the word equation for this reaction. |
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Answer» Solution : (a) Chlorine gas is released at anode during chloro-alkali process. Uses : It is USED in WATER treatment. Manufacture of PVC. Used as disinfectants and pesticides. Used in swimming pools, CFC.s etc. (b)Carbon dioxide `(CO_2) ` gas is evolved when sodium carbonate reacts with hydrochloric acid. When the gas is passed through lime water it turns milky (SHOWING that it is carbon dioxide) due to the formation of insoluble calcium carbonate. Metal carbonate / Metal hydrogen carbonate + Acid `to`Salt + Carbondioxide + Water. |
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| 8429. |
(a) Name first three members of Group 2 and 16. (b) Name any four metalloids. (c)' Which chemical properties were stressed by Mendeleev while formulating his Periodic Table? (d) Write the following elements in order of increasing atomic numbers : Magnesium, Lithium, Aluminium. (e) Give the electronic configuration of the following elements: Carbon, Phosphorus, Chlorine. |
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Answer» Solution :(a) First THREE MEMBERS of Group 2 are Be, Mg and CA. First three members of Group 16 are 0, S and Se. (b) Boron, silicon, germanium and arsenic are metalloids. (c) Formulae of hydrides and oxides formed by the elements. (d) Lithium `lt` MAGNESIUM `lt` Aluminium (e) `{:("Carbon:",2","4),("Phosphorus:",2","8","5),("Chlorine:",2","8","7):}` |
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| 8430. |
(a) Name a metal for each case :(i) It does not react with cold as well as hot water but reacts with steam.(ii) It does not react with any physical state of water.(b) When calcium metal is added to water, the gas evolved does not catch fire but the same gasevolved on adding sodium metal to water catches fire. Why is it so ? |
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Answer» Solution : (a) (i) Al, Fe and Zn do not react with cold as well as hot water but react with STEAM. (II) Lead, copper, silver, gold, etc., do not react with any physical state of water. (b) The reaction of calcium with water is less VIOLENT. The heat EVOLVED is not sufficient for hydrogen gas evolved to catch fire. |
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| 8431. |
(a) Most of the metals acquire a dull surface when exposed to air . Name the chemical phenomenon responsible for this process. (b) State the conditions under which the iron articles get rusted . Design an activity to investigate the conditions necessary for rusting . |
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Answer» SOLUTION :Silver chloride (AGCL) and Silver BROMIDE (AgBr) `2AgCl overset ("Sunlight")rarr2Ag+Cl_(2)` `2AgBr overset("Sunlight")rarr2Ag+Br` Those reactions in which energy is absorbed (in from of heat, light or ELECTRICITY ) to break down the rectants is cal |
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| 8432. |
A molecule of NH_(3) (ammonia) has … |
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Answer» only single BONDS. |
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| 8433. |
A molecule of a vegetable oil (X) contains one C=C double bond. How many moles of H_2will be needed for the hydrogenation of one mole of the oil X? |
| Answer» SOLUTION : For the complete hydrogenation of ONE mole of oil X, the mole of `H_2`needed is one. | |
| 8434. |
A molecule is the simplest structural unit of an element or compound which contains one or more atoms. |
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Answer» |
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| 8435. |
A molecule is a combination of two or more atoms held together by ……………… . |
| Answer» SOLUTION :CHEMICAL BONDS | |
| 8436. |
A molecule has 3 bonded pairs and 2 lone pairs on the central atom. Explain the shape of the molecule with an example. |
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Answer» SOLUTION :(i) expected shape with five bond pairs (II) DETERMINATION of number of HYBRID orbitals (iii) the expected shape of the molecule (iv) distortion due to lone pairs and resultant shape of the molecule |
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| 8437. |
A molecule has an octahedral geometry. So how many number of valence electrons should the central atom possess and are the number of valence electrons is the same if one, two bond pairs are successively replaced by lone pairs? What are the geometries of the molecules with one and two lone pairs? Explain with the help of hybridisation. |
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Answer» Solution :(i) RELATION between number of valence electron pairs (bond pairs and lone pairs) and geometry (II) number of valence electrons around CENTRAL atom for octahedral geometry |
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| 8438. |
A molecule 'AB_(5)' has five bond pairs around the central atom 'A'. If the bond pair of electrons are successively replaced by one, two and three lone pair of electrons, then what would be the preferred shapes of the molecules and how do they differ from actual geometry of AB_(5)? |
Answer» Solution :In `AB_(5)` molecule, central atom A is surrounded by five electron PAIRS and no lone pairs. Hence, the structure is a trigonal bipyramid and as there are no lone pairs, so the structure is not distorted. Here in this structure three bonded atoms OCCUPY equatorial positions of the triangle and other two axial positions (top and bottom) of hte equilateral triangle). When one of the bond pairs is replaced by a lone pair, the preferred position of the lone pair is equatorial and the geometry is distorted trigonal bipyramid because in this structure it experiences less number of REPULSIONS and hence stable.  When two bond pairs are replaced by lone pair of electrons, then the preferred geometry will be the one of lowest energy with minimum repulsions.When two lone pairs are present among five electron pairs allowed the central atom then the molecule experiences three types of repulsions and their order is p - 1. p `gt` 1. p - b. p `gt` b. p - b.p. The structure that has lesser repulsions is  The two lone pairs are separated by maximum bond angle of `120^(@)` and hence, the above structure is most preferred geometry that is T-SHAPE with minimum repulsions. When three bond pairs are replaced by a lone pair, then the preferred geometry is the one where three lone pairs occupy equatorial positions with maximum separation of bond angle and hence the shape is linear. 
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| 8439. |
A mixture of sodium carbonate and sodium bicarbonate was subjected to heating. Some loss in weight was found. How does this information help us tofind out thecomposition of mixture? |
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Answer» Solution :Between SODIUM carbonate and sodium bicarbonate, only sodium bicarbonate DECOMPOSES to given sodium carbonate, `CO_(2) and H_(2)O`. The GASEOUS products `(CO_(2) and H_(2)O)` ESCAPE out into theatmosphere. Therefore, an apparent loss in WEIGHT occurs during thereaction. This loss in weight corresponds to theamount of gaseous products formed . Fromed the mass of gaseous products formed, amount of sodium bicarbonate in the mixture can be obtained, andthus composition of the mixture of the mixture can be found out. |
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| 8440. |
A mixture of sand and sugar is an example of a |
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Answer» compound |
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| 8441. |
A mixture of oxygen and ethyne is burnt for welding. Can you tell why a mixture of ethyne and air is not used ? |
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Answer» Solution :Ethyne is an unsaturated hydrocarbon. Combustion of ethyne in air produces a yellow flame with lot of black SMOKE. DUE to this incomplete combustion, heat produced is very less than the heat required for welding, hence, the mixture of ethyne and air is not used for welding. When the combustion of ethyne is carried out with oxygen, due to complete combustion heat produced is very LARGE which is usually NEEDED for welding, hence the mixture of ethyne and oxygen is used for welding. `2[CH-=CH]+5O_(2)to4CO_(2)+2H_(2)O+` Heat and Light |
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| 8442. |
A mixture of oxygen and ethyne is burnt for welding. Can you tell why a mixture of ethyne and air is not used? |
| Answer» Solution :If a mixture of oxygen and ethyne is burnt, then ethyne burns completely producing a BLUE flame. The oxygen-ethyne flame is EXTREMELY hot and produces a very high TEMPERATURE which is USED for WELDING metals. A mixture of ethyne and air is not used for welding because burning of ethyne in air produces a sooty flame due to incomplete combustion, which is not hot enough to melt metals for welding. | |
| 8443. |
A mixture of oxygen and ethyne is burnt for welding . Can you tell why a mixture of ethyne and air is not used ? |
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Answer» Solution :`2HC-=CH+SO_(2)to4CO_(2)+2H_(2)O`+ HEAT When ethayne is burnt in air,it gives a sooty FLAME .Thisis due toincomplete combusition caused by limited supply of air.However if ethyne is burnt with oxygen,it gives a clean flame with temprature `3000^(@)C` because of COMPLETE combusition.This acetylene flame is used for welding.It is not possible to attain such a high temprature without mixing oxygen.This is the reason why a MIXTURE of ethyne and air is not used. |
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| 8444. |
A mixture of iron filings and sulphur is treated with a solvent in which sulphur dissolves. Name the solvent. |
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Answer» Water |
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| 8445. |
A mixture of chalk powder and water makes a |
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Answer» colloidal SOLUTION |
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| 8446. |
A mixture of cement, gravel, coarse sand and water is called |
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Answer» MORTAR |
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| 8447. |
A mixture of 0.75 mol of N_(2) and 1.20 mol of H_(2) is placed in a 3 L container. When the reaction N_(2)+3H_(2) hArr2NH_(3) reaches the equilibrium, the concentration of H_(2) is 0.1 M. Calculate the concentration of N_(2) and NH_(3) when the reaction is carried out with double the number of moles. |
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Answer» Solution :`N_(2) + 3H_(2) hArr 2NH_(3)` Concentration of `N_(2)=0.75//3=0.25` mol `L^(-1)` Concentration of `H_(2) =1.20//3=0.4 ` mol `L^(-1)` `N_(2) + 3H_(2) hArr 2NH_(3)` `{:("Initial concentration ",0.25,0.4,0),("At equilibrium",0.25-x,0.4-3x,2x):}` Concentration of `H_(2)` at equilibrium is given as =0.1 ` therefore 0.4-3x=0.1 implies x=0.1` Concenration of `N_(2)` at equilibrium=0.25-0.1 =0.15 Concentration of `NH_(3)` at equilibrium =`0.1xx2=0.2` When the reactiion is CARRIED with double the number of moles , concentration of `N_(2)=0.15xx2=0.3` mol `L^(-1)`and CONCENTRATIONOF `NH_(3)=0.2xx2=0.4` mol `L^(-1)`. |
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| 8448. |
A mixture is made of two substance . Carbon disulphide is added to the mixture. The substance that dissolves may be |
| Answer» ANSWER :C | |
| 8449. |
A mixture having 2 g of hydrogen and 32 oxygen occupies how much volume at NTP? |
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Answer» |
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| 8450. |
A mixture contains 95.5% ethanol and 4.5% water is called………………..and 100% pure ethanol is called…………………. |
| Answer» SOLUTION :RECTIFIED SPIRIT, ABSOLUTE ALCOHOL | |