Complete the following chemical reactions.
(i) PbS(s) + H2O2(aq) →
(ii) MnO-4(aq) + H2O2(aq) →
(iii) CaO(s) + H2O(g) →
(iv) AlCl3(g) + H2O(I) →
(v) Ca3N2(s) + H2O(I) →
Classify the above into (a) hydrolysis, (b) redox and (c) hydration reactions.
(i) PbS(s) + H2O2(aq) → PbSO4(s) + H2O(l)
H2O2 is acting as an oxidizing agent in the reaction. Hence, it is a redox reaction.
(ii) 2MnO-4(aq) + 5H2O2(aq) → 6H+(aq) → 2Mn2+(aq) + 8H2O(l) + 5O2(g)
H2O2(aq) is acting as a reducing agent in the acidic medium, thereby oxidizing MnO-4(aq). Hence, the given reaction is a redox reaction.
(iii) CaO(s) + H2O(g) → Ca(OH)2aq
The reactions in which a compound reacts with water to produce other compounds are called hydrolysis reactions. The given reaction is hydrolysis.
(iv) 2AlCl3(g) + 3H2O(I) → Al2O3(s) + 6HCl(aq)
The reactions in which a compound reacts with water to produce other compounds are called hydrolysis reactions. The given reaction represents hydrolysis of AlCl3.
(v) Ca3N2(s) + 6H2O(I) → 3Ca(OH)2(aq) + 2NH3(g)
The reactions in which a compound reacts with water to produce other compounds are called hydrolysis reactions. The given reaction represents hydrolysis of Ca3N2.
Justify the position of hydrogen in the periodic table on the basis of its electronic configuration.
Compare the structures of H2O and H2O2.
Write chemical reactions to show the amphoteric nature of water.
Arrange the following
(i) CaH2, BeH2 and TiH2 in order of increasing electrical conductance.
(ii) LiH, NaH and CsH in order of increasing ionic character.
(iii) H-H, D-D and F-F in order of increasing bond dissociation enthalpy.
(iv) NaH, MgH2 and H2O in order of increasing reducing property.
Discuss the principle and method of softening of hard water by synthetic ion-exchange resins.
What do you understand by the term “non-stoichiometric hydrides”? Do you expect this type of the hydrides to be formed by alkali metals? Justify your answer.
What is meant by 'demineralised' water and how can it be obtained?
What causes the temporary and permanent hardness of water?
How does H2O2 behave as a bleaching agent?
Why does hydrogen occur in a diatomic form rather than in a monoatomic form under normal conditions?
How do you account for the formation of ethane during chlorination of methane?
What are hybridisation states of each carbon atom in the following compounds ?
(i) CH2=C=O,
(ii) CH3CH=CH2,
(iii) (CH3)2CO,
(iv) CH2=CHCN,
(v) C6H6
What will be the minimum pressure required to compress 500 dm3 of air at 1 bar to 200 dm3 at 30°C?
What are the common physical and chemical features of alkali metals?
Calculate the molecular mass of the following:
(i) H2O
(ii) CO2
(iii) CH4
Assign oxidation number to the underlined elements in each of the following species:
(a) NaH2PO4
(b) NaHSO4
(c) H4P2O7
(d) K2MnO4
(e) CaO2
(f) NaBH4
(g) H2S2O7
(h) KAl(SO4)2.12 H2O
What is the basic theme of organisation in the periodic table?
Explain the formation of a chemical bond.
Choose the correct answer. A thermodynamic state function is a quantity
(i) used to determine heat changes
(ii) whose value is independent of path
(iii) used to determine pressure volume work
(iv) whose value depends on temperature only.
A liquid is in equilibrium with its vapour in a sealed container at a fixed temperature. The volume of the container is suddenly increased.
a) What is the initial effect of the change on vapour pressure?
b) How do rates of evaporation and condensation change initially?
c) What happens when equilibrium is restored finally and what will be the final vapour pressure?
Is there any change in the hybridisation of B and N atoms as a result of the following reaction?
BF3 + NH3 → F3B.NH3
Give the number of electrons in the species , H2 and
The best and latest technique for isolation, purification and separation of organic compounds is:
(a) Crystallisation
(b) Distillation
(c) Sublimation
(d) Chromatography
Nitrogen laser produces a radiation at a wavelength of 337.1 nm. If the number of photons emitted is 5.6 × 1024, calculate the power of this laser.
A welding fuel gas contains carbon and hydrogen only. Burning a small sample of it in oxygen gives 3.38 g carbon dioxide, 0.690 g of water and no other products. A volume of 10.0 L (measured at STP) of this welding gas is found to weigh 11.6 g. Calculate
(i) empirical formula,
(ii) molar mass of the gas, and
(iii) molecular formula.
Explain with the help of suitable example polar covalent bond.
How would you convert the following compounds into benzene?
(i) Ethyne (ii) Ethene (iii) Hexane
What are electrophiles and nucleophiles? Explain with examples.
How do you account for the formation of ethane during chlorination of methane?
Density of a gas is found to be 5.46 g/dm3 at 27 °C at 2 bar pressure. What will be its density at STP?