i) Name the method of refining of nickel
ii) what is the role of cryolite in the extraction of aluminium
iii) what is the role of limestone in the extraction of iron from its oxides ?
Define the following terms:
i)Lyophilic colloid
ii) Zeta potential
iii) Associated colloids
i) Lyophilic colloids are liquid loving colloids (Lyo means solvent and philic means loving). When these colloids are mixed with the suitable liquid, high force of attraction exists between colloidal particles and liquid. This result in the formation of very stable solution called lyophilic sol. These sols are formed by substances like gums, starch and proteins.
ii) Zeta Potential : zeta potential is the potential difference between the dispersion medium and the stationary layer of fluid attached to the dispersed particle.
iii) Association colloids are microheterogeneous systems in which the particles of the colloidal dispersed phase (micelles) are formed by the agglomeration of molecules or ions of the substance dissolved in the dispersion medium.
For the first order thermal decomposition reaction, the following data were obtained:
C2H5Cl (g) --> C2H4 (g) +HCl(g)
T/s Total pressure/atm
0 0.30
300 0.50
Calculate the rate constant
(Given: log 2=0.301, log =0.4771, log 4 =0.6021)
An element crystallizes in b.c.c lattice with cell edge of 500 pm. The density of the element is 7.5g cm-3. How many atoms are present in 300 g of the element ?
The elements of 3d transition series are given as:
Sc Ti V Cr Mn Fe Co Ni Cu Zn
Answer the following:
i) Write the element which shows a maximum number of oxidation states.Give reason.
ii) Which element has the highest m.p?
iii) Which elements shows only +3 oxidation state ?
iv) which element is a strong oxidising agent in +3 oxidation state and why?
Write the structure of an isomer of compound C4H9Br which is most reactive towards SN1 reaction.
Write the chemical equations involved in the following reactions:
i) Hoffmann-bromamide degradation reaction
ii) Carbylamine reaction
i) Write the structural difference between starch and cellulose.
ii) What type of linkage is present in Nucleic acid ?
iii) Give one example each for fibrous protein and globular protein.
i) What is the role of sulphur in the vulcanization of rubber?
ii) Identify the monomers in the following polymer:
iii)Arrange the following polymers in the increasing order of their intermolecular forces:
Terylene, polythene, Neoprene