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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.
| 1101. |
Which one of the following arrangement does not truly represent the property indicated against it ?A. `Br_(2) lt Cl_(2)lt F_(2)` Oxidising powerB. `Br_(2) lt Cl_(2) lt F_(2)` ElectronegativityC. `Br_(2) lt F_(2) lt Cl_(2)` Electron affinityD. `Br_(2) lt Cl_(2) lt F_(2)` Bond energy |
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Answer» Correct Answer - D Shond dissociation enthalphy of halogen follows the sequnecy as `Cl_(2) gt Br gt F_(2) gt I_(2)` Enthalpy of dissociation decreasss as the bond distance increases from `F_(2)` to `I_(2)` due to a corresponding increases in size of the atom as one move down the group from F to i. However, the F.F bond dissociation enthalpy is smaller than that of `Cl-Cl` (even than that of Br-Br) because repulsion between the lons pairs of electrons are very large. |
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| 1102. |
How does electron deficient compound `BF_(3)` achieve electronic saturation i.e., fully occupied outer electron shells ? |
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Answer» By the following two ways (i) Multiple bonding of `ppi-ppi` back bonding , e.g., `BF_(3)` in which a lone pair of electrons present in `2p-`orbital of one of the fluorine atoms may be transferred to the vacant p-orbital one the boron atom. (ii) Formation of complexes in which electronsare received from a donor molecule e.g., `F_(3)Brarr NH_(3)`. Boron compounds, thus, behaves as Lewis acids. |
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| 1103. |
Welding of magnesium can be done in an atmosphere ofA. XeB. HeC. KrD. Ne |
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Answer» Correct Answer - B Welding of Mg is done in the atmosphere of He due to its inert and non-inflammable nature . |
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| 1104. |
The formation of `O_(2)^(+)[PtF_(6)]^(-)` is the basis for the formation of xenon fluorides. This is because:A. `O_(2)`and `Xe` have comparable sizes.B. Both `O_(2)` and `Xe` are gases.C. `O_(2)` and `Xe` have comparable ionisation energies.D. `O_(2)` and `Xe` have comparable electronegativities. |
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Answer» Correct Answer - C In march `1962`, neil bartlett, then at the university of british columbia, observed the reaction of a noble gas. First, the prepared a red compound which is formulated as `O_(2)^(+)[PtF_(6)]^(-)` and it is already know that the first ionistion enthalpy of molecular oxygen `(1175 kJ mol-1)` is almost similar with that xenon `(1170 kJ mol-1)` then he made efforts to prepare same type of compound by mixing `PtF_(6)` and Xenon `Xe^(+)[PtF_(6)]^(-)`. After this discovery, a number of xenon compounds minly with most electronegative elements like fluorine and oxygen, have been synthesised. |
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| 1105. |
The noble gas which behaves abnormally in liquid state isA. `Xe`B. `Ne`C. `He`D. `Ar` |
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Answer» Correct Answer - C Liquid He is unique liquid as it exists in two forms, He`(I)` and He`(II)`.He`(I)` is a normal liquid with normal properties. On cooling to `2.19 k` and `38mm` pressure it changes to He `(II)` with abrupt changes in many physical properties such as density dielectric constant and specific heat. He `(II)` is super fluid or quantum mechanical liquid. it has very high heat of conductance `(600 " times of Cu ")`, low visosity `(1//10 " of " H_(2) " gas ")` and flat meniscus (a low surface tension). |
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| 1106. |
The ease of liquefation of noble gases decrease in the order:A. `HegtNegtArgtKrgtXe`B. `XegtKrgtArgtNegtHe`C. `KrgtXegtHegtArgtNe`D. `ArgtKrgtXegtHegtNe` |
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Answer» Correct Answer - B The case of liquefaction decrease with decrease in critial temperature. Also, critical temperature of a gas is lowered with increase in mol. Mass. |
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| 1107. |
The ease of liquefaction of noble gases decreases in the orderA. Hegt Negt Argt Krgt XeB. Xegt Kr gt Ar gtNegt HeC. Krgt Xe gt He gtArgt NeD. ArgtKr gt XegtHegtNe |
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Answer» Correct Answer - B Due to Vander der waals forces |
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| 1108. |
The ease of liquefaction of noble gases increases in the orderA. `He gt Ne gt Ar gt Kr gt Xe `B. `Xe gt Kr gt Ar gt He gt Ne `C. `He lt Ne lt Ar lt Kr lt Xe `D. `Xe lt He lt Ne lt Ar lt Kr ` |
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Answer» Correct Answer - C The ease of liquefication of noble gases increases in the order `He lt Ne lt Ar lt Kr lt Xe . ` |
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| 1109. |
Butter of tin is:A. `SnCl_(2).5H_(2)O`B. `SnBr_(4).5H_(2)O`C. `SnBr_(2).2H_(2)O`D. `SnCl_(4).5H_(2)O` |
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Answer» Correct Answer - D Chemically, butter of tin is `SnCl_(4).5H_(2)O` |
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| 1110. |
Elements of group `14` |
| Answer» both (b) and (d) are correct answers. The variable oxidation states are due to inert pari effect. | |
| 1111. |
Give the outer electronic configuration of noble gases. |
| Answer» The outer electronic configuration of noble gases is `ns^(2)np^(6)` (except He (`1s^(2)`) | |
| 1112. |
Assertion. Coloured cations can be identified by borax bead test. Reason. Transparent bead `(NaBO_(2) + B_(2)O_(3))` forms coloured bead with coloured cation.A. If both assertion and reason are true, and reason is the true explanation of the assertion.B. If both assertion and reason are true, but reason not is the true explanation of the assertion.C. If assertion is true, but reason is false.D. If both assertion and reason are false. |
| Answer» Correct Answer - A | |
| 1113. |
What types of cations are tested by borax bead test? |
| Answer» Cations involved in coloured salts | |
| 1114. |
Glass is a:A. gelB. polymeric mixtureC. supercooled liquidD. microcrystaline solid |
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Answer» Correct Answer - C Glass is hard, amorphous mixture, a cooled liquid of silicates of `Ca,Na` and other metals. |
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| 1115. |
The ability of a substance to exist in two or more crstaline forms knows as:A. IsomerismB. PolysomorphismC. IsomorphismD. Amorphism. |
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Answer» Correct Answer - B Ability of a substance to exist in two or more crystaline forms is called polyisomorphism. |
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| 1116. |
When metals X is treated with sodium hydroixdes , a white precipitate (A) is obtained , which is soluble in excess of `NaOH` to give souble complex (B). Compound (A) is souble in dilute HCl to form compound (C ). The compound (A) when heated strongly gives (D), which is used to extract metal. Identify (X), (A), (B), (C ) and (D). Write suitable equations to support their identities. |
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Answer» Since metal X reacts with `NaOH` to first give a white ppt. (A) which dissolves in excess of NaOH to give a soluble complex (B), therefore , metal (X) must be Al , ppt (A) must be `Al(OH)_(3)` and complex (B) must be sodium tetrahydroxoaluminate (III). `{:(underset((X))(2Al) + 3NaOH rarr underset(" Aluminium hydroxide (ppt.) ")(Al(OH)_(3)darr) + 3Na^(+)),(underset((A))(Al(OH)_(3))+NaOHrarr underset("Sod. tetrahydroxoaluminate (III)")underset((B))(Na^(+)[Al(OH)_(4)]^(-))):}` Since (A), i.e, `Al(OH)_(3)` react with dil. `HCl` to give compound (C), therefore, (C ) must be `AlCl_(3)`. `underset((A))(Al(OH)_(3)) + 3HCl rarr underset((C ))(AlCl_(3)) + 3H_(2)O` Since (A) on heating gives (D) which is used to extract metal (i.e, electrolysis of `Al_(2)O_(3)` gives Al metal), therefore , (D) must be alumina `(Al_(2)O_(3))` `underset((A))(2Al (OH)_(3)) overset(Delta)rarr underset((D)) (Al_(2)O_(3)) + 3H_(2)O` |
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| 1117. |
When conc. `HNO_(3)` is heated with `P_(2)O_(5)`, it formsA. `N_(2)O`B. `NO `C. `NO_(2)`D. `N_(2)O_(5)` |
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Answer» Correct Answer - D `4HNO_3 +2P_(2)O_(5) overset(Delta)to 2N_(2)O_(5)+4HPO_(3)` |
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| 1118. |
When conc. `H_(2)SO_(4)` is heated with `P_(2)O_(5),` the acid is converted toA. sulphur trioxideB. sulphur dioxideC. sulphurD. a mixture of sulphur dioxide and sulphur trioxide |
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Answer» Correct Answer - A When conc. `H_2SO_(4)` is heated with `P_(2)O_(5)` , the acid is coverted into sulphur trioxide . `underset("Conc.")(2H_2SO_(4))+2P_(2)O_(5) to underset("Sulphur trioxide ")(2SO_(3))+4HPO_(3)` |
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| 1119. |
Which of the following oxids is acidic in nature ?A. `B_(2)O_(3)`B. `Al_(2)O_(3)`C. `Ga_(2)O_(3)`D. `In_(2)O_(3)` |
| Answer» Correct Answer - A | |
| 1120. |
Which of the following is not known?A. `MCL_(5)`B. `ML_(3)`C. `SbCL_(30`D. `HCl_(3)` |
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Answer» Correct Answer - A `MCI_(5)` is not know because of absence of `d`-orbitals in nitrogen. |
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| 1121. |
White phosphorus containsA. `P_(2)` moleculesB. `P_(6)` moleculesC. `P_(4)` moleculesD. `P_(5)` melecules |
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Answer» Correct Answer - C White phoshphorus contains molecules of `P_(4)` |
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| 1122. |
Which one of the followig elements occur free in nature?A. NitrogenB. PhosphorusC. ArsenicD. Antimony |
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Answer» Correct Answer - A Atmospheric nitrogen is inert and unreactive because of very high bond energy `(945 kJ//mol)`. |
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| 1123. |
Which does not form complex?A. `N`B. `P`C. `As`D. `Bi` |
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Answer» Correct Answer - A Nitrogen does not form complexes because of the absence of `d`-orbitals. |
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| 1124. |
Nitrogen is inert because ofA. Low atomic sizeB. Pressence in gaseous stateC. More electronegativityD. Presence of triple bond |
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Answer» Correct Answer - D Nitrogen is inert because its `p`-subshell is half-filled due to it has maximum exchange energy. Thus it is exists in stable form as like inert gas and it form triple bond `(N-=N).N_(2)` molecules is very stable and its dissociation energy is `225 k cal//mol`. |
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| 1125. |
The oxidation state of nitrogen is highest inA. `NH_2OH`B. `N_3H`C. `N_2H_4`D. `NH_3` |
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Answer» Correct Answer - B `{:(-1,-2,-3,-1/3),(NH_2OH,N_2H_4,NH_3,N_3H):}` |
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| 1126. |
Which of the following has lowest dipole moment?A. `NH_3`B. `PH_3`C. `AsH_3`D. `SbH_3` |
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Answer» Correct Answer - D Electronegativity difference is minimum |
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| 1127. |
Nitrous oxide isA. soluble in hot waterB. soluble in cold waterC. insoluble in hot and cold waterD. acidic in nature |
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Answer» Correct Answer - B Physical property of Nitrous oxide |
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| 1128. |
Nitrous oxide isA. acidicB. basicC. amphotericD. Neutral |
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Answer» Correct Answer - D Nitrous oxide is a neutral gas . |
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| 1129. |
Which of the following represent laughing gas?A. `NO`B. `N_(2)O`C. `NO_(2)`D. `N_(2))_(3)` |
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Answer» Correct Answer - B When `N_(2)O` is inhaled in moderated quantities, it produces hysterical loughter, hence the name laughing gas. |
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| 1130. |
Which of the following is true for `N_(2)O_(5)`A. ParamagneticB. Anhydride of `HNO_(2)`C. Brown gasD. Exist in solid state in form of `[NO_(2)^(+)][NO_(3)^(-)]` |
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Answer» Correct Answer - D `N_(2)O_(5)` in solid form exists as `NO_(3)^(-)` and `NO_(2)^(-)` |
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| 1131. |
A solution of ammonia in water containsA. `H^(+)`B. `OH^(-)`C. Only `NH_(4)^(+)`D. `OH^(-),NH_(4)^(+)` and `NH_(4)OH` molecules |
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Answer» Correct Answer - D `NH_(3)`when dissolved in water forms `NH_(3)+H_(2)O to NH_(4)^(+) +OH^(-) hArr NH_(4)OH` |
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| 1132. |
Fixation of nitrogen meansA. conversion of free atmospheric nitrogen into nitrogen compoundsB. the action of dentrifying bacteria on nitrogen compoundsC. decomposition of nitrogenous compounds to yield free nitrogenD. reaction of nitrogen with oxygen |
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Answer» Correct Answer - A Definition |
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| 1133. |
Orthophosphoric acid on heating gives :A. Metaphosphoric acidB. PhosphineC. Phosphorus pentoxideD. Phosphorus acid |
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Answer» Correct Answer - A `underset"Orthophosphoric acid"(H_3PO_4) oversetDeltato underset"Metaphosphoric acid"(H_2O + HPO_3)` |
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| 1134. |
Polyphosphates are used as water softening agents because theyA. form soluble complexes with anionic speciesB. precipitate anionic speciesC. form soluble complexes with cationic speciesD. precipitate cationic species |
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Answer» Correct Answer - C `2Ca^(2+) + Na_2[Na_4(PO_3)_6] to 4Na^(+) + underset"(soluble)"(Na_2[Ca_2(PO_3)_6])` |
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| 1135. |
When orthophosphoric acid is heated to `600^(@)C` the product formed isA. `PH_(3)`B. `P_(2)O_(5)`C. `H_(3)PO_(3)`D. `HPO_(3)` |
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Answer» Correct Answer - D When orthophosphoric acid `(H_(3)PO_(4))` is heated and dehydraction takes place. It form metaphosphoric acid `(HPO_(3))`. `H_(3)PO_(4)overset(Delta)underset(600^(@)C)rarr HPO+H_(2)O` |
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| 1136. |
Write a short note on the hydrides of halogens. |
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Answer» Hydrides of halogens : Formation : `H_(2)+F_(2)overset("dark condition")to2HF` `H_(2)+Br_(2)overset("593 K")to2" HBr"` `H_(2)+Cl_(2)overset("Sun light")to2" HCl"` `H_(2)+I_(2)overset("713 K")to2" HI"` `to` These compounds dissolve in water to form hydrohalic acids. `{:(to,"Boiling points",,HF,,-,293" K"),(,,,HCl,,-,189" K"),(,,,HBr,,-,206" K"),(,,,HI,,-,238" K"):}` `to` The decreasing order of stability of these compounds is `HF gt HCl gt HBr gt HI` `to` The increasing order of acicid strength of these compounds `HF lt HCl lt HBr lt HI` |
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| 1137. |
Which has the lowest boiling point?A. `NH_(3)`B. `PH_(3)`C. `AsCl_(3)`D. `SbH_(3)` |
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Answer» Correct Answer - B In the hydrides of group 15, the boiling points changes as `underset(238.5 K)(NH_(3)) gt underset(185.5K)(PH_(3))lt underset(210.6 K)(AsH_(3)) lt underset(254.6K)(SbH_(3)) lt underset(290 K)(BiH_(3))` `:.` Generally mass increases then boiling point increases. The higher point of `NH_(3)` is due to excessive hydrogen bonding, so `PH_(3)` have lowest boiling point among hydrides of group number `15`, i.e, nitrogen family. |
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| 1138. |
`(NH_(4))_(2)Cr_(2)O_(7)` on heating gives a gas which is also given by :A. heating `NH_(4)NO_(2)`B. heating `NH_(4)NO_(3)`C. treating `Mg_(3)N_(2)` with `H_(2)O`D. treating Na (compound) with `H_(2)O_(2)` |
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Answer» Correct Answer - A `(NH_(4))_(2)Cr_(2)O_(7) to N_(2)+Cr_(2)O_(3)+4H_(2)O`. `N_(2)` gas is also given by `NH_(4)NO_(2)` `NH_(4)NO_(2) to N_(2)+2H_(2)O`. `NH_(4)NO_(3)` to `N_(2)O+2H_(2)O`. |
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| 1139. |
Polyphosphates are used for softening agents because theyA. form soluble complexes with anionic speciesB. precipitate anionic speciesC. form soluble complexes with cationic speciesD. preipitate cationic species |
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Answer» Correct Answer - C It sequesters `Ca^(2+)` and `Mg^(2+)` (present in hard water) and forms soluble complex with `Ca^(2+)` and `Mg^(2+)` which do not precipitate with `CO_(3)^(2-)` and soap. |
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| 1140. |
Electrolysis of aqueous solution of Brine (NaCI) givesA. `Cl_(2)`B. `H_(2)`C. `NaOH`D. None |
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Answer» Correct Answer - ABC |
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| 1141. |
27g of Al was treated with NaOH solution when a white gelatinous precipitate was obtained which upon strong heating gave an oxide. The amount of oxide (in g ) is |
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Answer» Correct Answer - `(51.0)` `underset(54 g)(2Al) overset(NaOH)rarr 2A(OH)_(3) overset(Delta)rarrunderset(102 g)(Al_(2)O_(3))` `54 g` of Al produce `Al_(2)O_(3) = 102//2 = 51.0 g` |
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| 1142. |
Statement-1. `Pb^(4+)` compounds are stronger oxidizing agent than `Sn^(4+)` compounds. Statement-2. The higher oxidation states for the group 14 elements are more stable for the heavier members of the group due to inert pair effect.A. Statement-1 is True, Statement-2 is True , Statement-2 is a correct explanation for statement-1.B. Statement-1 is True, Statement-2 is True , Statement-2 is not a correct explanation for statement-1.C. Statement-1 is True, Statement-2 is False.D. Statement-1 is False, Statement-2 is True. |
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Answer» Correct Answer - B Correct statement-2. The lower oxidation states for the group 14 elements are more stable for heavier members due to inert pair effect. |
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| 1143. |
Assertion. Al and Ga have nearly same atomic radii. Reason. Al and Ga diagonal relationship.A. If both assertion and reason are true, and reason is the true explanation of the assertion.B. If both assertion and reason are true, but reason not is the true explanation of the assertion.C. If assertion is true, but reason is false.D. If both assertion and reason are false. |
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Answer» Correct Answer - C Correct reason. Due to inert pair effect, Al and Ga have nearly same atomic radii. |
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| 1144. |
Select the Incorrect statement:A. (A) Perchioric acid is a stronger acid than sulphuric acidB. (B) Only one oxyacid [HOF] is formed by fluorineC. (C) The most stable oxy-acid of chlorine is perchioric acidD. (D) None of these |
| Answer» Correct Answer - D | |
| 1145. |
Identiity the incorrect statement among the following.A. (1) `Cl_2` reacts with excess of `NH_3` to give `N_2` and HClB. (2) `Br_2` reacts with hot and strong NaOH solution to give NaBr, `NaBrO_4` and `H_2O`.C. (3) Ozone reacts with `SO_2` to given `SO_3`D. (4) Silicon reacts with NaOH(aq) in the presence of air to give `Na_2SiO_3` and `H_2O`. |
| Answer» Correct Answer - B | |
| 1146. |
Give the uses of a) nitric aicd and b) ammonia. |
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Answer» Use of `"HNO"_(3)` : `to" HNO"_(3)` is used in the manufacture of ammonium nitrate for fertilisers and other nitrates for use in explosives and pyrotechnics. `to" HNO"_(3)` is used in the pickling of stainless steel. `to" HNO"_(3)` is used as oxidiser in rocket fuels. |
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| 1147. |
Write the chemical reactions that occur in the manufacture of nitric acid. |
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Answer» Chemical reactions involved in the manufacturing of `"HNO"_(3)`. `to` Oxidation of `"NH"_(3)` `4NH_(3)+5O_(2)underset(500"K",9"bar")overset("Pt")to4NO+6H_(2)O` `to NO_(2)` formation : `2NO+O_(2)iff2NO_(2)` `to` Formation of `"HNO"_(3)` : `3NO_(2)+H_(2)O to 2"HNO"_(3)+"NO"` |
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| 1148. |
Iron becomes passive in conc. `"HNO"_(3)` - Why ? |
| Answer» Iron becomes passive in conc. `"HNO"_(3)` due to formation of a passive film of oxide on the surface of iron. | |
| 1149. |
What happens when `O_(3)` is passed through KI soultion |
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Answer» `O_(3)` is passed through KI solution `I_(2)` is liberated `2"KI"+O_(3)+H_(2)O to2"KOH"+"I"_(2)+2O_(2)` |
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| 1150. |
What happens when `"KClO"_(3)` is heated with `"MnO"_(2)` |
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Answer» When `"KClO"_(3)` is heated with `"MnO"_(2)` and liberates oxygen gas. `2"KClO"_(3)underset("MnO"_(2)overset(Delta)to2"KCl"+3O_(2)` |
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