(i) 10 g of an organic compound was present in 100 cm3 of water. It was extracted twice with fresh 50 cm3portions of ether. How much organic compound was extracted ? (The organic compound is three times more soluble in ether than in water.)
(ii) Give one example each of homogeneous and heterogeneous catalysis.
(i) Name the crystal structure of the copper metal.
(ii) What is the coordination number of copper in its crystalline state ?
ΔH and ΔS for vaporization of water at 1 atm pressure are 40.63 KJ mole 1 and 108.8 JK– 1mole– 1 respectively. Calculate the temperature at which the free energy change for the transformation will be zero. Predict the sign of free energy change below this temperature.
(ii) The heat supplied to a Carnot engine is 1958.22 KJ. How much useful work can be done by the engine which works between 0 °C and 100 °C ?
Write balanced chemical equations for each of the following reactions :
(i) Sodium thiosulphate with aqueous silver nitrate.
(ii) Copper sulphate with aqueous potassium iodide.
(iii) Hydrogen peroxide with acidified ferrous sulphate solution.
(iv) Ozone with moist iodine.
Electro-thermal Process : Mixture of calcium phosphate (from Bone ash) sand and coke is introduced into a closed electric furnace through hopper by screw conveyor. Electric furnace is an Iron tank lined inside with refractory brick.
Outlet pipe at upper part connected to condensing system.
Electric arc is struck between two carbon electrode to maintain temperature 1775 K. At High temperature calcium phosphate react with sand to form calcium silicate and P2O5. Latter is reduced by coke to give phosphorous and CO.
2Ca3(PO4) +6SiO2 ---> 6CaSiO3+P4O10 +10C ---->10CO +P4
Give reasons :
(i) Hydrogen peroxide is used for restoring the colour of lead paintings.
(ii) Silicones are used as lubricants at both high and low temperatures.