Ncert Solutions Chemistry Class 11th
Get insights from 2k questions on Ncert Solutions Chemistry Class 11th, answered by students, alumni, and experts. You may also ask and answer any question you like about Ncert Solutions Chemistry Class 11th
- 2k
Questions
- 0
Discussions
- 1
Active Users
- 29
Followers
Have a question about Ncert Solutions Chemistry Class 11th? Ask our experts
Keep it short & simple. Type complete word. Avoid abusive language.
5.27. Assertion: At high altitudes, liquids boil at lower temperatures in comparison to that at sea level.
Reason: At high altitudes atmospheric pressure is high.
5.27. Assertion: At high altitudes, liquids boil at lower temperatures in comparison to that at sea level.
Reason: At high altitudes atmospheric pressure is high.
5.27. (c) At high altitudes atmospheric pressure is low. Therefore, liquids at high altitudes boil at lower temperatures in comparison to that at sea level. Since water boils at low temperature on hills, the pressure cooker is used for cooking food. In hospitals surgical instruments are steril
Upvote 
8.19. Balance the following equations in basic medium by ion-electron method and oxidation number methods and identify the oxidising agent and the reducing agent.
(a) P4(s) + OH–(aq) → PH3(g) + H2PO2–(aq)
(b) N2H4(l) + ClO–(aq) → NO(g) + Cl-(aq)
(c) Cl2O7(g) + H2O2(aq) → ClO2–(aq) + O2(g) + H+
8.19. Balance the following equations in basic medium by ion-electron method and oxidation number methods and identify the oxidising agent and the reducing agent.
(a) P4(s) + OH–(aq) → PH3(g) + H2PO2–(aq)
(b) N2H4(l) + ClO–(aq) → NO(g) + Cl-(aq)
(c) Cl2O7(g) + H2O2(aq) → ClO2–(aq) + O2(g) + H+
(a) Oxidation number method:
The oxidation number of P decreases from 0 to -3 and increases from 0 to +2. Hence, P4? is oxidizing as well as reducing agent.
During reduction, the total decrease in the oxidation number for 4 P atoms is 12.
During oxidation, total increase in the oxidation n
Upvote 5.26. Assertion: Intermolecular interactions may hold the closely and slowly moving molecules together and thus the solid liquifies.
Reason: Compression brings the molecules in close vicinity and cooling slows down the movement of molecules.
5.26. Assertion: Intermolecular interactions may hold the closely and slowly moving molecules together and thus the solid liquifies.
Reason: Compression brings the molecules in close vicinity and cooling slows down the movement of molecules.
5.26. (d) Compression brings the molecules in close vicinity and cooling slows down the movement of molecules therefore, intermolecular interactions may hold the closely and slowly moving molecules together and the gas liquifies.
Upvote 5.25. Assertion: Liquids and solids are hard to compress.
Reason: Magnitude of the repulsion rises very rapidly as the distance separating the molecules decreases.
5.25. Assertion: Liquids and solids are hard to compress.
Reason: Magnitude of the repulsion rises very rapidly as the distance separating the molecules decreases.
5.25. (a) Other than attractive forces, molecules also exert repulsive forces on one another. When two molecules are brought into close contact with each other, the repulsion between the electron clouds and that between the nuclei of two molecules comes into play. Magnitude of the repulsion ri
Upvote 8.18. Balance the following redox reactions by ion-electron method.
(a) MnO4–(aq) +I–(aq) → MnO2 (s) + I2 (s) (in basic medium)
(b) MnO4–(aq) + SO2(g) → Mn2+(aq) +H2SO4–(in acidic solution)
(c) H2O2 (aq) + Fe2+(aq) → Fe3+(aq) + H2O(l) (in acidic solution)
(d) Cr2O72- (aq) + SO2 (g) → Cr3+ (aq) + SO42-(aq) (in acidic solution)
8.18. Balance the following redox reactions by ion-electron method.
(a) MnO4–(aq) +I–(aq) → MnO2 (s) + I2 (s) (in basic medium)
(b) MnO4–(aq) + SO2(g) → Mn2+(aq) +H2SO4–(in acidic solution)
(c) H2O2 (aq) + Fe2+(aq) → Fe3+(aq) + H2O(l) (in acidic solution)
(d) Cr2O72- (aq) + SO2 (g) → Cr3+ (aq) + SO42-(aq) (in acidic solution)
(a) The balanced half reaction equations are:
Oxidation half equation:
I− (aq) → I2 (s) - (i)
Reduction half reaction equation:
MnO4− (aq) → MnO2 (aq) - (ii)
Balance I atoms and charges in the oxidation half reaction.
2I− (aq) → I2 (s) + 2e−
In the reduction half react
Upvote 5.24. Assertion: Viscosity of liquids decreases as the temperature rises.
Reason: Molecules of liquids are held together by attractive intermolecular forces.
5.24. Assertion: Viscosity of liquids decreases as the temperature rises.
Reason: Molecules of liquids are held together by attractive intermolecular forces.
5.24. (b) Viscosity of liquids decreases as the temperature rises because at high temperature molecules have high kinetic energy and can overcome the intermolecular forces to slip past one another between the layers.
Upvote Assertion and Reason:
Directions:
(a) Assertion and reason both are correct statements and reason is correct explanation for assertion.
(b) Assertion and reason both are correct statements but reason is not correct explanation for assertion.
(c) Assertion is correct statement but reason is wrong statement.
(d) Assertion is wrong statement but reason is correct statement.
5.23. Assertion: The dipole-dipole interactionbetween two HCl moleculesis stronger than the London forces.
Reason: Only partial charges are involved
Assertion and Reason:
Directions:
(a) Assertion and reason both are correct statements and reason is correct explanation for assertion.
(b) Assertion and reason both are correct statements but reason is not correct explanation for assertion.
(c) Assertion is correct statement but reason is wrong statement.
(d) Assertion is wrong statement but reason is correct statement.
5.23. Assertion: The dipole-dipole interactionbetween two HCl moleculesis stronger than the London forces.
Reason: Only partial charges are involved
5.23. (a) The dipole-dipole interaction between two HCl molecules is stronger than the London forces but is weaker than ion-ion interaction because only partial charges are involved.
Upvote 8.17. Consider the reactions:
(a) H3PO2(aq) + 4AgNO3(aq) + 2H2O(l) → H3PO4(aq) + 4Ag(s) + 4HNO3(aq)
(b) H3PO2(aq) + 2CuSO4(aq) + 2H2O(l) → H3PO4(aq) + 2Cu(s) + H2SO4(aq)
(c) C6H5CHO(l) + 2[Ag(NH3)2]+(aq) + 3OH–(aq→ C6H5COO–(aq) + 2Ag(s) + 4NH3(aq) + 2H2O(l)
(d) C6H5CHO(l) + 2Cu2+(aq) + 5OH–(aq) → No change observed
What inference do you draw about the behaviour of Ag+ and Cu2+ from these reactions?
8.17. Consider the reactions:
(a) H3PO2(aq) + 4AgNO3(aq) + 2H2O(l) → H3PO4(aq) + 4Ag(s) + 4HNO3(aq)
(b) H3PO2(aq) + 2CuSO4(aq) + 2H2O(l) → H3PO4(aq) + 2Cu(s) + H2SO4(aq)
(c) C6H5CHO(l) + 2[Ag(NH3)2]+(aq) + 3OH–(aq→ C6H5COO–(aq) + 2Ag(s) + 4NH3(aq) + 2H2O(l)
(d) C6H5CHO(l) + 2Cu2+(aq) + 5OH–(aq) → No change observed
What inference do you draw about the behaviour of Ag+ and Cu2+ from these reactions?
Reactions (a) and (b) indicate that H3PO2 (hypophosphorous acid) is a reducing agent and thus reduces both AgNO3 and CuSO4 to Ag and Cu respectively. Conversely, both AgNO3 and CuSO4 act as oxidising agent and thus oxidise H3PO2to H3PO4 (orthophosphoric acid) Rea
Upvote 8.16. Why does the following reaction occur?
XeO64– (aq) + 2F– (aq) + 6H+(aq) → XeO3(g)+ F2(g) + 3H2O(l)
What conclusion about the compound Na4XeO6 (of which XeO64– is a part) can be drawn from the reaction?
8.16. Why does the following reaction occur?
XeO64– (aq) + 2F– (aq) + 6H+(aq) → XeO3(g)+ F2(g) + 3H2O(l)
What conclusion about the compound Na4XeO6 (of which XeO64– is a part) can be drawn from the reaction?
XeO64−? oxidizes F− and F− reduces XeO64−?
Hence, the given reaction occurs.
The oxidation number of Xe decreases from +8 to +6. The oxidation number of F increases from -1 to 0.
Thus, Na4? XeO6? is a stronger oxidising agent than F−.
Upvote 8.15. Justify giving reactions that among halogens, fluorine is the best oxidant and among hydrohalic compounds, hydroiodic acid is the best reductant.
8.15. Justify giving reactions that among halogens, fluorine is the best oxidant and among hydrohalic compounds, hydroiodic acid is the best reductant.
Fluorine oxidizes chloride ion to chlorine, bromide ion to bromine and iodide ion to iodine respectively.
F2? + 2Cl− → 2F− + Cl2?
F2? + 2Br− → 2F− + Br2?
F2? + 2I− → 2F− + I2?
Chlorine oxidizes bromide ion to bromine and iodide ion to iodine.
Cl2? + Br− → 2Cl− + Br2?
Cl2? + I− → 2Cl− + I2?
Bromine o
Upvote