

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.
901. |
`H_(2)O_(2)` and heavy water was discovered by respectively :A. Thernard, UreyB. Urey, RutherfordC. Aston, UreyD. Aston, Chadwick |
Answer» Correct Answer - A | |
902. |
Which of the following statements about `H_(2)O_(2)` is not true ?A. Both oxidising and reducing agentB. Two hydroxyl group of `H_(2)O_(2)` lie in the same planeC. Same structure in liquid and solid formD. None of these |
Answer» Correct Answer - B | |
903. |
Heavy water isA. De-mineralised waterB. De-ionized waterC. Ordinary water containing dissolved salts of heavy metalsD. It is the compounds of heavier isotope of hydrogen with oxygen `(D_(2)O)` |
Answer» Correct Answer - D | |
904. |
The dihedral angle in gaseous `H_(2)O_(2)` isA. `180^(@)`B. `90^(@)`C. `111.5^(@)`D. `109^(@)-28` |
Answer» Correct Answer - c Gaseous `H_(2)O_(20` has dihedral angle equal to `111.5^(@)` |
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905. |
The structure of `H_(2)O_(2)` isA. Open book likeB. Closed book likeC. PyramidalD. Linear |
Answer» Correct Answer - A | |
906. |
The dihedral angle in gaseous `H_(2)O_(2)` isA. `111.5^(@)`B. `90.2^(@)`C. `94.8^(@)`D. `101.9^(@)` |
Answer» Correct Answer - B | |
907. |
The dihedral angle in gaseous `H_(2)O_(2)` isA. `180^(@)`B. `90^(@)`C. `111.5^(@)`D. `109^(@)-28'` |
Answer» Correct Answer - C | |
908. |
Statement-1. HF is an electron-precise hydride. Statements-2. In HF,F has three lone pairs of electrons.A. Statement-1 is true, Statement-2 is True , Statement-2 is a correct explanation for statement-2B. Statement-1 is True, Statement-2 is True, Statement-2 is not a correct explanation for statement-2C. Statement-1 is True, Statement -2 is FalseD. Statement -1 is False , Statement-2 is True. |
Answer» Correct Answer - D Correct Statement-1. HF is an electron-rich hydride. |
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909. |
Assertion ` NH_(3)` is an electron precise hydride. Reason `: NH_(3)` has one loone pair of electrons on `N` atom. |
Answer» Correct Answer - d `ddot(N)H` is elelctron rich hydride. `NH_(3)` contain one lone pair of electron on nitrogen. |
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910. |
Select the correct statement for heavy water.A. It is less denser than common waterB. It is an oxide of deuteriumC. It has a heavy or bad tasteD. It has a heavier isotope of oxygen |
Answer» Correct Answer - b Heavy water contains heavy hydrogen `(._(1)^(2)H)`, formula of heavy water is `._(1)^(2)H_(2)O` or `D_(2)O` |
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911. |
Can phosphorus with other electronic configuration `3s^(2) 3p^(3)` from `PH_(5)` ? |
Answer» Although P shows oxidation states of +3 and +5 , it cannot form `PH_(5)` . Due to high `Delta_(H-H)` (435.88 KJ `mol^(-1)`) and slightly negative `Delta`eg H(-73 KJ `mol^(-1)`) dihydrogen acts only as a weak oxidising agent. Therefore, it can oxidise P to +3 oxidation state but not to its highest oxidation state of +5 . Thus, P forms `PH_(3)` but not `PH_(5)` | |
912. |
Is `H_(2)O_(2)` planar in nature? |
Answer» No, `H_(2)O_(2)` has a non-planar structure. | |
913. |
There is a smaple of 10 volume of hydrogen peroxide solution . Calculate its strength.A. `1%`B. `3%`C. `10%`D. `90%` |
Answer» Correct Answer - b 10 volume solution of `H_(2)O_(2) `is `3.035 %` solution. `i.e., 3.035 g `of `H_(2)O_(2)` is present in `100 ml` of the solution. |
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914. |
`H_(2)O_(2)` is always stored in black bottles because |
Answer» `H_(2)O_(2)` is stored in wax-lined glass or plastic vessels in dark. | |
915. |
Given below are the two reactions of `H_(2)O_(2)`. Mark the correct statement which follows. (i) `2KMnO_(4) + 3H_(2)SO_(4) + 5H_(2)O_(2) to K_(2)SO_(4) + 2MnSO_(4) + 8H_(2)O + 5O_(2)` (ii) `2Cr(OH)_(3) + 4NaOH + 3H_(2)O_(2) to 2Na_(2)CrO_(4) + 8H_(2)O`A. (i) Show oxidising nature of `H_(2)O_(2)` and (ii) shows reducing nature of `H_(2)O_(2)`.B. In (i) `H_(2)O_(2)` acts as a reducing agent and in (ii) it acts as an oxidising agent.C. In both (i) and (ii), `H_(2)O_(2)` acts as an oxidising agent.D. In both (i) and (ii), `H_(2)O_(2)` acts as a reducing agent. |
Answer» Correct Answer - B In (i) `H_(2)O_(2)` reduces `KMnO_(4)` to `MnSO_(4)` and is oxidised to `O_(2)`. In (ii)`H_(2)O_(2)` oxidises `Cr(OH)_(3)` to `Na_(2)CrO_(4)` and is reduced to `H_(2)O`. |
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916. |
The isotopes of hydrogen have different physical properties due to difference in mass. They have almost same chemical properties with a difference in their rates of reactions which is mainly due toA. their different enthalpy of bond dissociationB. different electronic configurationsC. different atomic massesD. different physical properties. |
Answer» Correct Answer - A Enthalpy of bond dissociation of deuterium is higher `(443.35 " kJ mol"^(-1))` than hydrogen `(435.88" kJ mol"^(-1))`. |
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917. |
The volume of oxygen liberated at STP from 15 mL of 20 volume `H_(2)O_(2)` isA. 100 mLB. 150 mLC. 200 mLD. 300 mL |
Answer» Correct Answer - D 1 mL of 20 volume `H_(2)O_(2)` liberates `O_(2)` at STP =20 mL `therefore ` 15 mL of `H_(2)O_(2)` will liberate `O_(2)` at STP `=15xx20=300 `mL |
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918. |
The volume of oxygen liberated from `15 ml` of 20 volume `H_(2)O_(2)` isA. `250 ml`B. `300 ml`C. `150 ml`D. `200 ml` |
Answer» Correct Answer - B Quantity of `H_(2)O_(2)=15 ml` and volume of `H_(2)O_(2)=20`. We know that 20 volume of `H_(2)O_(2)` means 1 litre of this solutin will give 20 litres of oxygen at `N.T.P.` Since, oxygen liverated from `1000 ml(1` litres `)` of `H_(2)O_(2)=20` litres, therefore oxygen liberate from `15 ml` of `H_(2)O_(2)=(20)/(1000)xx15=0.3`litre `=300ml`. |
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919. |
Concentrated sulphuric acid cannot be used drying H2. Why? |
Answer» Cone. H2SO4 on absorbing water from moist H2 produces so much heat that H2 catches fire. |
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920. |
Complete the following reaction (i) Na + H2 → (ii) N2 + H2 → (iii) CO + H2 \(\overset{700\,K}{\underset{Cobalt\,catalyst}{\longrightarrow}}\) (iv) H2 + Cl2 \(\overset{Sunlight}{\longrightarrow}\)(v) H2 + Br2 → (vi) CuO(s) + H2 \(\overset{heat}{\longrightarrow}\) |
Answer» (i) Na + H2 → 2NaH (ii) N2(g)+ H2(g)→ 2NH3(g) (iii) CO + H2 \(\overset{700\,K}{\underset{Cobalt\,catalyst}{\longrightarrow}}\) CH3OH (iv) H2(g) + Cl2(g) \(\overset{Sunlight}{\longrightarrow}\) 2HCl(g) (v) H2 + Br2 \(\overset{Sunlight}{\longrightarrow}\) 2HBr (vi) CuO(s) + H2 \(\overset{heat}{\longrightarrow}\) Cu + H2O |
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921. |
The boiling point of heavy water isA. `100^(@)`B. `101.4^(@)C`C. `99^(@)C`D. `110^(@)C` |
Answer» Correct Answer - B | |
922. |
Heavy water is qualified as heavy because it is:A. a heavy liquidB. an oxide of a heavier isotope of oxygenC. an oxidex of deuteriumD. denser of water |
Answer» Correct Answer - c |
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923. |
Heavy water is so called becauseA. it is highly dense and viscousB. it is an oxide of heavier isotope of hydrogenC. it is as heavy as mercuryD. its formula is `D^(2)O` |
Answer» Correct Answer - B | |
924. |
Water can act asA. an acidB. baseC. reductantD. oxidant |
Answer» Correct Answer - A::B::C::D | |
925. |
Heavy water is not used for drinking because :A. It is poisonousB. It is costlyC. Its physiological action is different from ordinary waterD. Its chemical properties are different from ordinary water |
Answer» Correct Answer - C | |
926. |
Sodium zeolite is_____. |
Answer» Correct Answer - Hydrate sodium alumininosilicate Hydrate sodium alumininosilicate |
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927. |
An ionic hydride of an alkali metal has significant covalent character and is almost unreactive towards oxygen and chlorine . This is used in the synthesisi of other useful hydrides. Write the formula of this is used in the synthesis of other hydrides. Write the formula of this hydride. Write its reaction with `Al_(2)Cl_(6)`. |
Answer» The alkali metal hydride with significant covalent character is lithium hydride (LiH). Actually ionisation enthalpy of lithium is quite high `(Delta_(i)H_(1)=520kJ mol^(-1))` and its size is also small (atomic radius=123Å). Its compounds are generally covalent in nature. `8LiH(s)+Al_(2)Cl_(6)(aq) to underset("Lithium aluminium hydride")(2LiAlH_(4)(aq)+6LiCl(s))` |
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928. |
An ionic hydride of an alkali metal has significant covalent character and is almost unreactive towards oxygen and chlorine. This is used in the synthesis of other useful hydrides . Write the formula of this hydride . Write its reaction with `Al_(2)Cl_(6)`. |
Answer» Since an ionic hydride of an alkali metal has significant covalent character, therefore, the hydride will be of the smallest alkali metal (Li) , i.e., LiH, Since LiH is very stable, therefore, it is almost unreactive towards `O_(2) and Cl_(2)` It reacts with `Al_(2)Cl_(6)` to form lithium aluminium hydride. `8LiH + Al_(2)Cl_(6) to 2LiAlH_(4) + 6LiCl`. |
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929. |
(i) What mass of hydrogen peroixde will be present in 2 L of a 5 molar solution ? (ii) Caluclate the mass of oygen which will be liberated by the decomposition of 200 mL of this solution. |
Answer» `"Molarity of solution"=("Mass of" H_(2)O_(2)//"Molar mass")/("Volume of solution in litres")` `(5 molL^(-1))=("Mass of" H_(2)O_(2)//(34g mol^(-1)))/(2L)` `"Mass of "H_(2)O_(2)=(5 mol L^(-1))xx(2L)xx(34gmol^(-1))=340g` Mass of oxygen `(O_(2))` liberated `"Mass of "H_(2)O_(2)(l) "in 200mL of solution"=(340g)/(2L)xx(0.2L)=34g` `underset(68g)2H_(2)O_(2)(l) to 2H_(2)O(l)+underset(32g)(O_(2)(g))` `"Mass of" O_(2)(g) "liberated by 68g of" H_(2)O_(2)=32g` `"Mass of" O_(2)(g) "liberated by 34g of" H_(2)O_(2)=16g` |
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930. |
Can distilled water be called as deionised water? |
Answer» Yes, distilled water does not contain any cations and anions and hence can be called as deionized water. |
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931. |
Give an example each of an ionic hydride and a covalent hydride. |
Answer» Ionic : NaH or CaH2 Covalent: H2O, B2H6, CH4 etc. |
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932. |
Which of the two hydrogen or deuterium undergoes reactions more rapidly and why? |
Answer» Hydrogen undergoes reactions more rapidly than deuterium. This is because of mass differences. For example, reaction between hydrogen and chlorine is about 14 times faster than between deuterium and chlorine. |
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933. |
Find the volume strength of 2N H2O2 solution. |
Answer» Volume strength = 5.6 × Normality Volume strength = 5.6 × 2 = 11.2 volumes |
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934. |
What are carbonate hardness and non - carbonate hardness? |
Answer» Temporary hardness is also called carbonate hardness. Permanent hardness is also called non-carbonate hardness. |
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935. |
What happens when heavy water is added to calcium carbonate? |
Answer» Deutero acetylene is formed. CaC2 + 2D2O → Ca(OD)2 + C2D2 |
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936. |
Concentrated sulphuric acid cannot be used for drying H2. Why? |
Answer» Conc. H2SO4 on absorbing water from moist H2 produces so much heat that H2 catches fire. |
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937. |
Find the volume strength of `2N H_(2)O_(2)` solution. |
Answer» Correct Answer - 11.2 volume | |
938. |
Can sodium bicarbonate make water hard? |
Answer» Sodium bicarbonate cannot make water hard because soaps themselves are sodium salts of fatty acids which are soluble in water. |
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939. |
Calculate the strength of 5 volume `H_(2)O_(2)` solution ? |
Answer» Correct Answer - 15.18 `gL^(-1)` | |
940. |
Calculate the concentration in gram/litres of a 20 volume `H_(2)O_(2)` solution. |
Answer» Correct Answer - 60.7 g/l | |
941. |
Dilute solution of hydrogen peroxide cannot be heated strongly for its concentration. Explain. |
Answer» Dilute solution of H2O2 cannot be concentrated by heating because it decomposes into H2 and O2 on heating. H2O2 \(\overset{heat}{\longrightarrow}\) H2 + O2 |
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942. |
The hardness of water sample containing `0*002` mole of magnesium sulphate dissolved in a litre of water is expressed asA. 20 ppmB. 200 ppmC. 2000 ppmD. 120 ppm. |
Answer» Correct Answer - B Amount of `MgSO_(4)=0*002xx120xx1000=240`mg Now 120 mg `MgSO_(4)-=100" mg "CaCO_(3)` 240 mg `MgSO_(4)-=200" mg "CaCO_(3)` 12 of water contains 200 mg `CaCO_(3)` or `10^(6)` mg water contains 200 mg `CaCO_(3)`. Degree of hardness = 200 ppm |
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943. |
What do you understand by terms hydrolysis and hydration? Give examples. |
Answer» Due to high dielectric constant, it has a very strong hydrating tendency. It dissolves many ionic compounds. However, certain covalent and some ionic compounds are hydrolysed in water.Examples- P4 O10 (s) +6H2 O ----------> 4H3 PO4( aq) SiCl 4 +2H2 O ----------> SiO2( s) + 4HCl |
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944. |
Assign the reason for the following:(a) Enthalpy of fusion of water is higher as compared to the hydrides of Sulphur & Selenium. (b) Water is quite stable and does not dissociate in to its elements even at high temperature. |
Answer» a) Due hydrogen bond it has high latent heat of fusion b) Water is a stable compound and its decomposition is not thermodynamically feasible |
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945. |
Assertion : In gaseous phase, `H_(2)O` and `H_(2)O_(2)` both have bent structures. Reason Bond angle of both `H_(2)O` and `H_(2)O_(2)` is `04.5^(@)`.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 assertion.C. If assertion is true but reason is false.D. If both assertion and reason are false. |
Answer» Correct Answer - D In gaseous phase, water molecule has a bent structure with a bond angle of `104.5^(@)`, whereas, `H_(2)O_(2)` has a non-planar structure both in gas and solid phases. The dihedral angle in gas and solid phase is `111.5^(@)` and `90.2^(@)` respectively. |
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946. |
The hardness of water sample containing 0.002 of water is expressed as :A. 20 ppmB. 200 ppmC. 2000 ppmD. 120 ppm |
Answer» Correct Answer - B Amount of `MgSO_(4)=0.002xx120xx1000` `=120` mg Now 120 mg `MgSO_(4)-=100 mg CaCO_(3)` `therefore` 240 mg `MgSO_(4)-=200 mg CaCO_(3)` 1 L of water contains =200 mg of `CaCO_(3)` or `10^(6)` mg `H_(2)O` contains =200 mg of `CaCO_(3)` `therefore ` Degree of hardness =200 ppm. |
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947. |
What is the mass of hydrogen peroxide present in 1 litre of 2M solution? Calculate the volume of oxygen at STP liberated upon complete decomposition of 100 cm3 of the above solution. |
Answer» Step 1: To calculate the mass of H2O2 in 1 litre of 2M solution. Molecular mass of H2O2 = 2 × 1 + 2 × 16 = 34 amu By definition, 1 litre of 1M H2O2 contains 34 g of H2O2 1 litre of 2M H2O2 will contain H2O2 = 34 × 2 = 68 g Step 2 : To calculate the volume of O2 liberated at STP from 100cm3 of 2M solution. 1 litre 2M H2O2 solution contains H2O2 = 68 g 100 cm3 of 2M H2O2 solution will contain \(\frac{68}{1000}\) × 100 = 6.8g of H2O2 The equation representing the decomposition of H2O2 is 2H2O = 2 × 34 = 68g → 2H2O + O2 22400cm3 at STP Now 68 g of H2O2 at STP give O2 = 22400 cm3 k of O2 6.8 g of H2O2 at STP will evolve O2 = \(\frac{22400}{68}\) x 6.8 = 2240cm3 = 2.24 mL reg |
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948. |
Which of the following is not true ?A. Hardness of water deprnds on its behaviour towards soapB. The temporary hardness is due to the presence of Ca and Mg bicarbonatesC. Permanent hardness is due to the presence of soluble Ca and Mg sulphates, chloride and nitratesD. Permanent hardness can be removed by boiling the water. |
Answer» Correct Answer - D Permanent hardness can not be removed by boiling the water but temporary hardness can be removed. |
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949. |
Atomic hydrogen combaines with almost all elements but molecular hydrogen does not. Explain. |
Answer» Atomic hydrogen is formed by passing hydrogen gas through lungsten electrodes at `2000 "to" 3000^(@)C` and under low pressure. This means that energy associated with atomic hydrogen is more than energy associated with molecular hydrogen. Therefore, atomic hydrogen is more reactive and combines. `H_(2)(g) underset(acr)overset("Electric")to 2H` |
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950. |
Find the volume strength of 1.6 N H2O2 solution. |
Answer» We know that strength = Normality × Eq. wt; and Eq. wt of H2O2 = 17 Strength of 1.6 N H2O2 solution = 16 × 17 g/1 Now 68 g of H2O2 gives 22400 ml O2 at NTP 16 × 17 g of H2O2 will give \(\frac{22400}{68}\) × 1.6 × 17 = 8960 ml of O2 at NTP But 1.6 × 17 g of H2O2 are present in 1000 ml of H2O2 solution Hence 1000 ml of H2O2 solution gives 8960 ml of O2 at STP 1ml of H2O2 solution will give = \(\frac{8960}{1000}\) = 8.96 ml of O2 at NTP Hence the volume strength of 1.6N H2O2 solution = 8.96 volume |
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