52671 + Interview Questions in Chemistry in Class 11

1.	Assertion : In atomic form hydrogen consists of one proton and one electron. Reason : In elemental form hydrogen exists as a diatomic molecule and is called dihydrogen.
Answer» If both assertion and reason are true and reason is the correct explanation of assertion. If both assertion and reason are true but reason is not the correct explanation of assertion. If assertion is true but reason is FALSE. If both assertion and reason are false. SOLUTION :Atomic number of hydrogen is 1. Hence it has 1 PROTON. Also for a neutral ATOM, number of protons is equal to the number of electrons hence it has 1 electron. It does not have any NEUTRON.

Discussion

2.	Assertion : In case of isoelectronic ions the ionic size increases with the increase in atomic number. Reason: The greater the attraction of nucleus , greater is the ionic radius.
Answer» If both assertion and REASON are true and the reason is the correct EXPLANATION of the assertion If both assertion and reason are true butreason isnot the correct explanation of the assertion If assertion is true but reason is false If the assertion and reason both are false Solution :Both assertion and reason are false. In case of isoelectronic , i.e., ions, having the same number of electrons and different NUCLEAR charge, the size decreases with increase in ATOMIC NUMBERS.

Discussion

3.	Assertion. In a unit cell of NaCl , all Cl^- ions touch Na^+ ion as all well they touch each other . Reason. Radius ratio r_+//r_- in NaCl is 0.414.
Answer» If both assertion and REASON are true, and reason is the true explanation of the assertion. If both assertion and reason are true, but reason is not the true explanation of the assertion. If assertion is true , but reason is false If both assertion and reason are false. SOLUTION :Correct A . In a unit cell of NaCl, all `Cl^-` ions touch `Na^+` ION but do not touch each other. Correct R . Actual RADIUS ratio `r_(Na^+)//r_(Cl^-)` is 0.525 and not 0.414

Discussion

4.	Assertion : In a gaseous reaction, the ratio of the volumes of gaseous reactants and products is in agreement with their molar ratio Reason :This is according to Avogadro's hypothesis.
Answer» If both ASSERTION and REASON are CORRECT and reason is correct EXPLANATION for assertion If both assertion and reason are correct but reason is not correct explanation for assertion If assertion is correct but reason is incorrect If both assertion and reason are incorrect Solution :Reason is the correct explanation for assertion

Discussion

5.	Assertion : In a fission reaction a heavy nucleus is broken into three fragement of nearly equal mass . Reason: The binding energy per nucleon for a heavy nuclei is less than the binding energy per nucleon of the fragments.
Answer» Both A and R are TRUE and R is the CORRECT explanation of A Both A and R are true but R is not a correct explanation of A A is true but R is false Both A and R are false Answer :D

Discussion

6.	Assertion. If the length of the unit cell of LiCl having NaCl structure is 5.14 Å , the ionic radius ofCl^(-) ion is 1.82 Å.Reason . Anion-anion contact is retained in LiCl structurebeacause anions constitute the lattice.
Answer» SOLUTION :If anion -anion contact is retained , then as shown in the adjoining fig, Interionic distance of LICL = `a/2` ` ( 5.14 Å)/2 = 2.57Å ` `BC = sqrt(AB^(2) + AC^(2)) = sqrt((2.57)^(2) + ( 2.57)^(2))`= 3.63 Å Radius of ` Cl^(-) "ION" = 1/2 BC = 1/2 xx 3.63= 1.81 Å` Hecne, R is the correct explanation of A.

Discussion

7.	Assertion: If BOD level of water in a reservoir is less than 5ppm, it is highly polluted.Reason: High biological oxygen demand means low activity of bacteria in water
Answer» ANSWER :C

Discussion

8.	Assertion : Ice cube floats on water. Reason : Density of ice is less than that of water.
Answer» If both ASSERTION and REASON are TRUE and reason is the CORRECT EXPLANATION of assertion. If both assertion and reason are true but reason is not the correct explanation of assertion. If assertion is true but reason is false. If both assertion and reason are false. Answer :A

Discussion

9.	Assertion : Hydrogen resembles halogens. Reason : It has high ionisation energy but still form H^+ ion.
Answer» Both assertion and reason are TRUE and reason is the CORRECT explanation of assertion. Both assertion and reason are true but reason is not the correct explanation of assertion. Assertion is true but reason is false Both Assertion and reason are false Answer :B

Discussion

10.	Assertion : Hydrogen resembles both, alkali metals as well as halogens. Reason : Hydrogen forms oxides, halides and sulphides, and exists as diatomic molecule.
Answer» If both assertion and reason are true and reason is the CORRECT EXPLANATION of assertion. If both assertion and reason are true but reason is not the correct explanation of assertion. If assertion is true but reason is FALSE. If both assertion and reason are false. Answer :A

Discussion

11.	Assertion : Hydrogen is the simplest atom Reason : Its nucleus contains only two protons
Answer» Both ASSERTION and REASON are true and reason is the CORRECT EXPLANATION of assertion. Both assertion and reason are true but reason is not the correct explanation of assertion. Assertion is true but reason is false Both Assertion and reason are false Answer :C

Discussion

12.	Assertion: Hydrogen combines with other elements by losing, gaining or sharing electrons. Reason:Hydrogen forms electrovalent and covalent bonds with other elements .
Answer» SOLUTION :(a) REASON is the CORRECT EXPLANATION for ASSERTION.

Discussion

13.	Assertion : Hydrogen atom is combine with other element by exchange and sharing of electron. Reason : Hydrogen can be form electrovalent or covalent bond with other elements.
Answer» Both ASSERTION (A) and REASON (R) are true and Reason (R) is the CORRECT EXPLANATION of Assertion (A) Both (A) and (R) are true but (R) is not the correct explanation of (A) (A) is true but (R) is false (A) and (R) both are false. Answer :A

Discussion

14.	Assertion. Hydrogen has one electron in its orbit but it produces several spectral lines Reason. There are many excited energy levels available
Answer» If both ASSERTION and REASON are TRUE, and reason is the true explanation of the arrertion If both assertion and reason are true, but reason is not the true explanation of the assertional If assertion is true, but reason is false If both assertion and reason are false Answer :A

Discussion

15.	Assertion : Hydrides of N, O and F have lower boiling points than the hydrides of their subsequent group members. Reason : Boiling point depends upon the molecular mass only.
Answer» If both ASSERTION and reason are true and reason is the correct EXPLANATION of assertion. If both assertion and reason are true but reason is not the correct explanation of assertion. If assertion is true but reason is FALSE. If both assertion and reason are false. Solution :Boiling point depends upon INTERMOLECULAR forces. Due to higher electronegativity of N, O and F, the magnitude of hydrogen bonding in their hydrides will be quite high. Hence their biling points will be higher than the hydrides of their subsequent GROUP members.

Discussion

16.	Assertion : Hydrides of group 13 elements are Lewis acids whereas hydrides of group 15-17 elements are Lewis bases. Reason : Group 13 hydrides have few electrons whereas group 15-17 hydrides have excess electrons which are present as lone pairs.
Answer» If both assertion and REASON are true and reason is the correct EXPLANATION of assertion. If both assertion and reason are true but reason is not the correct explanation of assertion. If assertion is true but reason is FALSE. If both assertion and reason are false. ANSWER :A

Discussion

17.	Assertion : Hydrazine contains nitrogen but does not give Lassaigne's test for hydrogen. Reason : Hydrazine reacts with fused sodium to give H_(2) gas.
Answer» If both assertion and Reason are true, and reason is the true explanation of the assertion. If both assertion and reason are true, but reason is not the true explanation of the assertion. If assertion is true, but reason is false If both assertion and reason are false Solution :Correct explanation. Hydrazine does not CONTAIN carbon. Therefore, NaCN cannot be FORMED which is essential for positive test for NITROGEN.

Discussion

18.	Assertion: Hybridisation influences the bond length and bond enthalpy in organic compound. Reason: More the s character of hybrid orbital, shorter and stornger will be the bond.
Answer» If both ASSERTION and REASON are TRUE and reason is the CORRECT EXPLANATION of assertion If both assertion and reason are true but reason is not the correct explanation of assertion If assertion is true but reason is false. If both assertion and reason are false. Answer :A

Discussion

19.	Assertion. HNO_(3) renders ironpassive. Reason. Iron reacts with HNO_(3) to form ferric nitate.
Answer» If both ASSERTION and reason are TRUE, and is the correct EXPLANATION of the assertion. If both assertion and reason are true, but reason is not the correct explanation of the assertion. If assertion is true, but reason is false. If both assertion and reason are false Solution :Correct reason. `HNO_(3)` reacts with Fe to FORM a thin impervious layer of ferrosoferric oxide `(FeO.Fe_(2)O_(3)-=Fe_(3)O_(4))` on the surface of iron which protects it from further action.

Discussion

20.	Assertion : HNO_(3) makes iron passive. Reason : HNO_(3) forms a protective layer of ferric nitrate on the surface of iron.
Answer» Both assertion and reason are correct STATEMENTS, and reason is the correct explanation of the assertion. Both assertion is and reason are correct statements, but reason is not the correct explanation of the assertion. Assertion is correct, but reason is WRONG statement. Assertion is wrong but reason is correct statement. Solution :Correct reason `HNO_(3)` forms a PROTECTIVE layer of ferrosoferric oxide on the surface of iron.

Discussion

21.	Assertion : HNO_(2) can act both as a reducing agent and an oxidising agent. Reason : In HNO_(2), oxidation state of nitrogen is +3 which can change from -3 to +5.
Answer» If both ASSERTION and REASON are TRUE and reason is the CORRECT EXPLANATION of assertion. If both assertion and reason are true but reason is not the correct explanation of assertion. If assertion is true but reason is false. If both assertion and reason are false. Answer :A

Discussion

22.	Assertion : Higher order ionization constants (K_(a_(2)),K_(a_(3))) are smaller than the lower order ionization constant (K_(a_(1))) of polyprotic acid. Reason : Polyprotic acid solutions contain a mixture of acids.
Answer» If both assertion and reason are TRUE and reason is the CORRECT explanation of assertion. If both assertion and reason are true but reason is not the correct explanation of assertion. If assertion is true but reason is false. If both assertion and reason are false. Solution :The reason for samaller values of HIGH order ionixation constants is that it is more difficult to remove a positively charged PROTON from a negative ION due to electrostatic forces.

Discussion

23.	Assertion: Heterolytic fission occurs readily in polar covalent bonds. Reason: Hyterolytic fission involves breaking of bond in such a way that the shared pair of electrons go with one atom.
Answer» If both assertion and reason are true and reason is the correct explanation of assertion If both assertion and reason are true but reason is not the correct explanation of assertion If assertion is true but reason is false. If both assertion and reason are false. Solution :In polar covalent BOND, shapred pair of electrons is displaced towards the more ELECTRONEGATIVE atom and hence in heterolytic fission, the electron pair is EASILY TAKEN away by more electronegative atom.

Discussion

24.	Assertion : HF_(z)^(-)ions exist in solid and liquid state but not exist in equines solution. Reason : The Hydrogen bond HF - HF is more but Jess strong them HF and H_(2)O .
Answer» ASSERTION (A) and Reason (R) both are CORRECT and (R) GIVES correct EXPLANATION. Assertion (A) and Reason (R) correct, but Reason is not proper reason. Assertion is correct, but Reason is WRONG. Assertion and Reason both incorrect. Solution :Assertion and Reason both are correct and Reason gives correct explanation.

Discussion

25.	Assertion: Helium has the highest value of ionization energy among all the elements known Reason: Helium has the highest value of electron affinity among all the elements known
Answer» Both assertion and REASON are true and reason is correct explanation for the assertion Both assertion and reason are true but the reason is not the correct explanation for the assertion Assertion is true and the reason is false Both assertion and the reason are false Answer :C

Discussion

26.	Assertion : Heterolytic fission occurs readily in polar covalent bonds. Reason : Heterolytic fission involves the breaking of bonf in such a way that the shared pair of electrons goes with one atom.
Answer» If both ASSERTION and reason are correct and reason is correct EXPLANATION for assertion. If both assertion and reason are correct but reason is not correct explanation for assertion. If assertion is correct but reason is incorrect. If both assertion and reason are incorrect. Solution :Correct explanation : Heterolytic fission INVOLVES the breaking of bond is such a way that the shared PAIR of electrons goes with the more electronegative atom.

Discussion

27.	Assertion :Helium has the highest value of ionisation energy among all the elements known Reason : Helium has the highest value of electron affinity among all the elements known
Answer» Both ASSERTION - and reason are TRUE and reason is correct EPLANATION for the assertion Both assertion and reason are true but the reason is not the correct explanation for the assertion Assertion is true and the reason is false Both assertion and the reason are false Answer :C

Discussion

28.	Assertion: Helium and beryllium have similar outer electronic configuration. Reason: Both are chemically inert.
Answer» Both A and B TRUE and R is the CORRECT explanation A Both A and R are true but R is not a correct explanation of A A is true but R is FALSE A is false but R is true Answer :C

Discussion

29.	Assertion : Heavy water acts as a moderator in nuclear reactors. Reason : Heavy water absorbs fast moving electrons.
Answer» Both A and R are true and R is the CORRECT explanation of A Both A and R are true but R is not a correct explanation of A A is true but R is false A is false but R is true Answer :C

Discussion

30.	Assertion. Heatof neutralisation for both HNO_(3) and HCl with NaOH is53.7 kJ per mole. Reason. NaOH is a strong electrolyte// base
Answer» If both A and R are TRUE,andR is the TRUEEXPLANATION of A. If both A and R are true,but R is not the true explanation of A. If A is true, but R is false If both A and R are false. Answer :B

Discussion

31.	Assertion. Heat energy is completely transformed into work during the isothermal expansion of an ideal gas. Reason . During an isothermal process, the change in internal energy of a gas due to decrease in pressure is nullified by the change due to increase in volume.
Answer» If both A and R are TRUE,andR is the TRUEEXPLANATION of A. If both A and R are true,but R is not the true EXPLANATION of A. If A is true, but R is false If both A and R are false. Answer :A

Discussion

32.	Assertion : Haber's synthesis of NH_(3) is carried out in the presence of a catalyst. Reason: the catalyst shifts the position of the equilibrium of the reaction N_(2)(g)+3H_(2)(g) hArr 2NH_(3)(g) tothe product side.
Answer» if both assertion and REASON are CORRECT and reason is correctexplanation for assertion. if both assertion and reason are correct but reason is not correct explanation for assertion. if assertion is correct but reason is incorrect. if assertion and reason boht are incorrect. Solution :Correct reason. A CATALYST lowers the height of ENERGY barrier. As a result , the speeds of both forward and backward reactions increase.

Discussion

33.	Assertion : H_(3)PO_(3) is a dibasic acid. Reason : Two H-atoms are directly attached to phosphorus 'P'.
Answer» If both ASSERTION and REASON are CORRECT, and Reason is the correct EXPLANATION of Assertion. If both Assertion and Reason are correct, but Reason is not the correct explanation of Assertion. If Assertion is correct, but Reason is INCORRECT. If Assertion is incorrect, but Reason is correct. Solution :N//A

Discussion

34.	Assertion. H_(3)PO_(3) is a dibasic acid. Reason. There are two H atoms directly attached to P.
Answer» If both ASSERTION and reason are TRUE, and is the correct explanation of the assertion. If both assertion and reason are true, but reason is not the correct explanation of the assertion. If assertion is true, but reason is false. If both assertion and reason are false Solution :Correct reason. There are two OH groups DIRECTLY ATTACHED to P.

Discussion

35.	Assertion : H_(3)BO_(3) is monobasic Lewis acid but its salt Na_(3)BO_(3) exists. Reason : H_(3)BO_(3) reacts with NaOH to give Na_(3)BO_(3).
Answer» If both Assertion and REASON are correct, and Reason is the correct EXPLANATION of Assertion. If both Assertion and Reason are correct, but Reason is not the correct explanation of Assertion. If Assertion is correct, but Reason is incorrect. If Assertion is incorrect, but Reason is correct. Solution :`H_(3)BO_(3)+NaOH to NaB(OH)_(4)` `3C_(2)H_(5)OH+H_(3)BO_(3) to (C_(2)H_(5))_(3)BO_(3)+3H_(2)O` `(C_(2)H_(5))_(3)BO_(3) +3NaOH to Na_(3)BO_(3)+3C_(2)H_(2)OH`

Discussion

36.	Assertion: H_(2)O_(2) reduces Cl_(2) "to" HCl. Reason: H_(2)O_(2) is highly Cl_(2) "to" HCl
Answer» Solution :(C ) Correct REASON. `H_(2)O_(2)` can act as reducing agent

Discussion

37.	Assertion. H_(2)O_(2) liberates O_(2) when it reacts with acidified KMnO_(4) solution. Reason. KMnO_(4) oxidises H_(2)O_(2) to O_(2)
Answer» ANSWER :A

Discussion

38.	Assertion . H_(2)O_(2) has higher boiling point than water. Reason. The dipole moment of H_(2)O_(2) is little more than that of H_(2)O.
Answer» Solution :CORRECT EXPLANATION. `H_(2)O_(2)` is more HIGHLY associated than `H_(2)O`

Discussion

39.	Assertion : H_(2)O_(2) is stored in wax-lined glass or plastic vessels. Reason : H_(2)O_(2) decomposes slowly on exposure to light.
Answer» If both assertion and reason are true and reason is the CORRECT explanation of assertion. If both assertion and reason are true but reason is not the correct explanation of assertion. If assertion is true but reason is false. If both assertion and reason are false. Solution :`H_(2)O_(2)` DECOMPOSES slowly on exposure to light. `2H_(2)O_(2(l))to 2H_(2)O_((l))+O_(2(g))` In the presence of metal surfaces or traces of alkali (PRESENT in glass containers), the above REACTION is catalysed. Hence, `H_(2)O_(2)` is STORED in wax-lined glass or plastic containers in dark.

Discussion

40.	Assertion. H_(2)O_(2) can be used as an antichlor in bleaching . Reason. It oxidises HCl to Cl_(2).
Answer» Solution :CORRECT reason. `H_(2)O_(2)` REDUCES EXCESS `Cl_(2) ` to `Cl^(-)` ions.

Discussion

41.	Assertion. H_(2)O is the only hydride of group 16 which is a liquid at ordinary temperature . Reason. In ice, each oxygen atom is surrounded by two covalent bonds and two hydrogen bonds.
Answer» Solution :Correct explanation. Due to extensive H-bonding , water exists as ASSOCIATED MOLECULES . As a result, it has HIGH b.p. and thus water is a LIQUID at ROOM temperature.

Discussion

42.	Assertion : H_2Ohas high melting point and boiling point than H_2S, H_2Se . Reason: H_2Ocontaining hydrogen bond
Answer» Both Assertion (A) and Reason (R) are true and Reason (R) is the correct EXPLANATION of Assertion (A) Both (A) and (R) are true but (R) is not the correct explanation of (A) (A) is true but (R) is FALSE (A) and (R) both are false. Answer :A

Discussion

43.	Assertion . H_(2) O is the only hybride of group -16 which is liquid ordinary tempratyre . Reason . In ice , oxygen atom is surrounded by two covalent bonds and two hydrogen bonds .
Answer» If both assertion and reason are correct, and reason is the correct explanation of the assertion. If both assertion and reason are correct , but reason is not the correct explanation of the assertion. If assertion is correct, but reason is incorrect . If both assertion and reason are incorrect. Solution :Correct explanation . `H_(2)O` is a LIQUID due to extensive hydrogen bonding and hence has high BOILING POINT.

Discussion

44.	Assertion: H_(2) molecule is more stable than He. Reason : Non-bonding pair in He make it unstable.
Answer» Assertion (A) and Reason (R) both are correct and (R) gives correct EXPLANATION. Assertion (A) and Reason (R) correct, but Reason is not PROPER reason. Assertion is correct, but Reason is WRONG. Assertion and Reason both incorrect. Solution :Assertion is correct, but Reason is wrong.

Discussion

45.	Assertion . H_(2)molecule is more stable than HeH molecule. Reason . The antibonding elelctron in the molecule destabilises is .
Answer» If both assertion and reason are CORRECT, and reason is the correct explanation of the assertion. If both assertion and reason are correct , but reason is not the correct explanation of the assertion. If assertion is correct, but reason is incorrect . If both assertion and reason are incorrect. Solution :Correctexplanation . `H_(2)` molecular is more stable than HEH because bond order of `H_(2)` = 1 and that of Heh ` = (1)/(2)`(Higher the bond order , MOREIS the stability).

Discussion

46.	Assertion . H_(2), Li_(2) and B_(2) each has a bond order of 1 and hence are equally stable. Reason . Stability of molecule/molecular ion depends only on bond order.
Answer» If both assertion and reason are correct, and reason is the correct explanation of the assertion. If both assertion and reason are correct , but reason is not the correct explanation of the assertion. If assertion is correct, but reason is INCORRECT . If both assertion and reason are incorrect. Solution :Correct A. `H_(2) , Li and B_(2)`are not equally stable . Correct R. The stability of molecules/molecular ions does not DEPEND only on bond order . (It depends upon other factors LIKE bond length , number of ELECTRONS present in antibonding molecular orbitals, ETC.)

Discussion

47.	Assertion : H^+ ion has a very low polarising power. Reason : Size of H^+ ion is very large
Answer» Both assertion and REASON are TRUE and reason is the correct explanation of assertion. Both assertion and reason are true but reason is not the correct explanation of assertion. Assertion is true but reason is false Both Assertion and reason are false Answer :D

Discussion

48.	Assertion : H_2 act as a reducing agent and react with many organic compounds in presence of catalyst and give hydrogenated product. Reason: CH_2=CH_2+H_2 underset"390 K"overset"[Ni]" to CH_3-CH_3
Answer» Both Assertion (A) and REASON (R) are true and Reason (R) is the CORRECT EXPLANATION of Assertion (A) Both (A) and (R) are true but (R) is not the correct explanation of (A) (A) is true but (R) is FALSE (A) and (R) both are false. Answer :A

Discussion

49.	Assertion . H-S-H bond angle in H_(2)S is closer to90^(@) but H-O-H bond angle in H_(2)O is 104.5^(@). Reason . Lp-lp repulsion us stronger ub H_(2)Sthan in H_(2)O
Answer» If both assertion and REASON are correct, and reason is the correct explanation of the assertion. If both assertion and reason are correct , but reason is not the correct explanation of the assertion. If assertion is correct, but reason is INCORRECT . If both assertion and reason are incorrect. SOLUTION :Correct explanation . Bond pair -bond pair repulsion are greater in `H_(2)O` than in `H_(2)S` because O-atom is smaller in SIZE than S-atom .

Discussion

50.	Assertion : Graphite is good conductor of heat and electricity . Reason : All the electrons of graphite are arranged in C-C type and formsigma -bond.
Answer» Statement Assertion and Reason both are RIGHT. Statement Reason is CORRECT EXPLANATION of statement Assertion. Statement Assertion and Reason both are right , but Assertion is not correct explanation of statement Assertion. Statement Assertion is right but statement Reason is wrong Both statement Assertion and Reason are wrong . SOLUTION :Statement Assertion is right but statement Reason is wrong

Discussion

Explore topic-wise InterviewSolutions in Current Affairs.

Assertion : In atomic form hydrogen consists of one proton and one electron. Reason : In elemental form hydrogen exists as a diatomic molecule and is called dihydrogen.

Assertion : In case of isoelectronic ions the ionic size increases with the increase in atomic number. Reason: The greater the attraction of nucleus , greater is the ionic radius.

Assertion. In a unit cell of NaCl , all Cl^- ions touch Na^+ ion as all well they touch each other . Reason. Radius ratio r_+//r_- in NaCl is 0.414.

Assertion : In a gaseous reaction, the ratio of the volumes of gaseous reactants and products is in agreement with their molar ratio Reason :This is according to Avogadro's hypothesis.

Assertion : In a fission reaction a heavy nucleus is broken into three fragement of nearly equal mass . Reason: The binding energy per nucleon for a heavy nuclei is less than the binding energy per nucleon of the fragments.

Assertion. If the length of the unit cell of LiCl having NaCl structure is 5.14 Å , the ionic radius ofCl^(-) ion is 1.82 Å.Reason . Anion-anion contact is retained in LiCl structurebeacause anions constitute the lattice.

Assertion: If BOD level of water in a reservoir is less than 5ppm, it is highly polluted.Reason: High biological oxygen demand means low activity of bacteria in water

Assertion : Ice cube floats on water. Reason : Density of ice is less than that of water.

Assertion : Hydrogen resembles halogens. Reason : It has high ionisation energy but still form H^+ ion.

Assertion : Hydrogen resembles both, alkali metals as well as halogens. Reason : Hydrogen forms oxides, halides and sulphides, and exists as diatomic molecule.

Assertion : Hydrogen is the simplest atom Reason : Its nucleus contains only two protons

Assertion: Hydrogen combines with other elements by losing, gaining or sharing electrons. Reason:Hydrogen forms electrovalent and covalent bonds with other elements .

Assertion : Hydrogen atom is combine with other element by exchange and sharing of electron. Reason : Hydrogen can be form electrovalent or covalent bond with other elements.

Assertion. Hydrogen has one electron in its orbit but it produces several spectral lines Reason. There are many excited energy levels available

Assertion : Hydrides of N, O and F have lower boiling points than the hydrides of their subsequent group members. Reason : Boiling point depends upon the molecular mass only.

Assertion : Hydrides of group 13 elements are Lewis acids whereas hydrides of group 15-17 elements are Lewis bases. Reason : Group 13 hydrides have few electrons whereas group 15-17 hydrides have excess electrons which are present as lone pairs.

Assertion : Hydrazine contains nitrogen but does not give Lassaigne's test for hydrogen. Reason : Hydrazine reacts with fused sodium to give H_(2) gas.

Assertion: Hybridisation influences the bond length and bond enthalpy in organic compound. Reason: More the s character of hybrid orbital, shorter and stornger will be the bond.

Assertion. HNO_(3) renders ironpassive. Reason. Iron reacts with HNO_(3) to form ferric nitate.

Assertion : HNO_(3) makes iron passive. Reason : HNO_(3) forms a protective layer of ferric nitrate on the surface of iron.

Assertion : HNO_(2) can act both as a reducing agent and an oxidising agent. Reason : In HNO_(2), oxidation state of nitrogen is +3 which can change from -3 to +5.

Assertion : Higher order ionization constants (K_(a_(2)),K_(a_(3))) are smaller than the lower order ionization constant (K_(a_(1))) of polyprotic acid. Reason : Polyprotic acid solutions contain a mixture of acids.

Assertion: Heterolytic fission occurs readily in polar covalent bonds. Reason: Hyterolytic fission involves breaking of bond in such a way that the shared pair of electrons go with one atom.

Assertion : HF_(z)^(-)ions exist in solid and liquid state but not exist in equines solution. Reason : The Hydrogen bond HF - HF is more but Jess strong them HF and H_(2)O .

Assertion: Helium has the highest value of ionization energy among all the elements known Reason: Helium has the highest value of electron affinity among all the elements known

Assertion : Heterolytic fission occurs readily in polar covalent bonds. Reason : Heterolytic fission involves the breaking of bonf in such a way that the shared pair of electrons goes with one atom.

Assertion :Helium has the highest value of ionisation energy among all the elements known Reason : Helium has the highest value of electron affinity among all the elements known

Assertion: Helium and beryllium have similar outer electronic configuration. Reason: Both are chemically inert.

Assertion : Heavy water acts as a moderator in nuclear reactors. Reason : Heavy water absorbs fast moving electrons.

Assertion. Heatof neutralisation for both HNO_(3) and HCl with NaOH is53.7 kJ per mole. Reason. NaOH is a strong electrolyte// base

Assertion. Heat energy is completely transformed into work during the isothermal expansion of an ideal gas. Reason . During an isothermal process, the change in internal energy of a gas due to decrease in pressure is nullified by the change due to increase in volume.

Assertion : Haber's synthesis of NH_(3) is carried out in the presence of a catalyst. Reason: the catalyst shifts the position of the equilibrium of the reaction N_(2)(g)+3H_(2)(g) hArr 2NH_(3)(g) tothe product side.

Assertion : H_(3)PO_(3) is a dibasic acid. Reason : Two H-atoms are directly attached to phosphorus 'P'.

Assertion. H_(3)PO_(3) is a dibasic acid. Reason. There are two H atoms directly attached to P.

Assertion : H_(3)BO_(3) is monobasic Lewis acid but its salt Na_(3)BO_(3) exists. Reason : H_(3)BO_(3) reacts with NaOH to give Na_(3)BO_(3).

Assertion: H_(2)O_(2) reduces Cl_(2) "to" HCl. Reason: H_(2)O_(2) is highly Cl_(2) "to" HCl

Assertion. H_(2)O_(2) liberates O_(2) when it reacts with acidified KMnO_(4) solution. Reason. KMnO_(4) oxidises H_(2)O_(2) to O_(2)

Assertion . H_(2)O_(2) has higher boiling point than water. Reason. The dipole moment of H_(2)O_(2) is little more than that of H_(2)O.

Assertion : H_(2)O_(2) is stored in wax-lined glass or plastic vessels. Reason : H_(2)O_(2) decomposes slowly on exposure to light.

Assertion. H_(2)O_(2) can be used as an antichlor in bleaching . Reason. It oxidises HCl to Cl_(2).

Assertion. H_(2)O is the only hydride of group 16 which is a liquid at ordinary temperature . Reason. In ice, each oxygen atom is surrounded by two covalent bonds and two hydrogen bonds.

Assertion : H_2Ohas high melting point and boiling point than H_2S, H_2Se . Reason: H_2Ocontaining hydrogen bond

Assertion . H_(2) O is the only hybride of group -16 which is liquid ordinary tempratyre . Reason . In ice , oxygen atom is surrounded by two covalent bonds and two hydrogen bonds .

Assertion: H_(2) molecule is more stable than He. Reason : Non-bonding pair in He make it unstable.

Assertion . H_(2)molecule is more stable than HeH molecule. Reason . The antibonding elelctron in the molecule destabilises is .

Assertion . H_(2), Li_(2) and B_(2) each has a bond order of 1 and hence are equally stable. Reason . Stability of molecule/molecular ion depends only on bond order.

Assertion : H^+ ion has a very low polarising power. Reason : Size of H^+ ion is very large

Assertion : H_2 act as a reducing agent and react with many organic compounds in presence of catalyst and give hydrogenated product. Reason: CH_2=CH_2+H_2 underset"390 K"overset"[Ni]" to CH_3-CH_3

Assertion . H-S-H bond angle in H_(2)S is closer to90^(@) but H-O-H bond angle in H_(2)O is 104.5^(@). Reason . Lp-lp repulsion us stronger ub H_(2)Sthan in H_(2)O

Assertion : Graphite is good conductor of heat and electricity . Reason : All the electrons of graphite are arranged in C-C type and formsigma -bond.