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.
Discuss the principle and method of softening of hard water by synthetic ion-exchange resins.
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.
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?
At 700 K, equilibrium constant for the reaction:
H2 (g) + I2 (g) ↔ 2HI (g)
is 54.8. If 0.5 mol L–1 of HI(g) is present at equilibrium at 700 K, what are the concentration of H2(g) and I2(g) assuming that we initially started with HI(g) and allowed it to reach equilibrium at 700K?
(a) How many sub-shells are associated with n = 4?
(b) How many electrons will be present in the sub-shells having ms value of –1/2 for n = 4?
The type of hybridisation of boron in diborane is
(a) sp (b) sp2 (c) sp3 (d) dsp2
Write Lewis dot symbols for atoms of the following elements: Mg, Na, B, O, N, Br.
Explain why the following systems are not aromatic?
Write IUPAC names of the following compounds :
What are the harmful effects of photochemical smog and how can they be controlled?
Does the number of moles of reaction products increase, decrease or remain same when each of the following equilibria is subjected to a decrease in pressure by increasing the volume?
(a) PCl5 (g) ↔ PCl3 (g) + Cl2 (g)
(b) CaO (s) + CO2 (g) ↔ CaCO3 (s)
(c) 3Fe (s) + 4H2O (g) ↔ Fe3O4 (s) + 4H2 (g)
Draw the structure of (i) BeCl2 (vapour) (ii) BeCl2 (solid).
What are allotropes? Sketch the structure of two allotropes of carbon namely diamond and graphite. What is the impact of structure on physical properties of two allotropes?