What is the difference between the terms 'hydrolysis' and 'hydration'?
Hydrolysis is defined as a chemical reaction in which hydrogen and hydroxide ions (H+ and OH- ions) of water molecule react with a compound to form products. For example:
NaH + H2O → NaOH + H2
Hydration is defined as the addition of one or more water molecules to ions or molecules to form hydrated compounds. For example:
CuSO4 + 5H2O → CuSO4 . 5H2O
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?
Write reactions to justify amphoteric nature of aluminium.
The solubility of Sr(OH)2 at 298 K is 19.23 g/L of solution. Calculate the concentrations of strontium and hydroxyl ions and the pH of the solution.
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?
If the velocity of the electron in Bohr’s first orbit is 2.19 × 106 ms–1, calculate the de Broglie wavelength associated with it.
Although both CO2 and H2O are triatomic molecules, the shape of H2O molecule is bent while that of CO2 is linear. Explain this on the basis of dipole moment.
What is the relationship between the members of following pairs of structures? Are they structural or geometrical isomers or resonance contributors?
(a)
(b)
(c)
The best and latest technique for isolation, purification and separation of organic compounds is:
(a) Crystallisation
(b) Distillation
(c) Sublimation
(d) Chromatography
Calculate the wavelength, frequency and wave number of a light wave whose period is 2.0 × 10–10 s.
Describe the effect of :
a) addition of H2
b) addition of CH3OH
c) removal of CO
d) removal of CH3OH on the equilibrium of the reaction: 2H2(g) + CO (g) ↔ CH3OH (g)
At 0°C, the density of a certain oxide of a gas at 2 bar is same as that of dinitrogen at 5 bar. What is the molecular mass of the oxide?