Classify the following into elements, compounds and mixtures : (a) Sodium (b) Soil ( c) Sugar solution (d) Silver (e) Calcium carbonate (f) Tin (g) Silicon (h) Coal (i) Air (j) Soap (k) Methane (1) Carbon dioxide (m) Blood

Predict the formulas of the stable binary compounds that would be formed by the combination of the following pairs of elements. (a) Lithium and oxygen (b) Magnesium and nitrogen (c) Aluminium and iodine (d) Silicon and oxygen (e) Phosphorus and fluorine (f) Element 71 and fluorine

Which separation techniques will you apply for the separation of the following ? (a) Sodium chloride from its solution in water. (b) Ammonium chloride from a mixture containing sodium chloride and ammonium chloride. ( c) Small pieces of metal in the engine oil of a car. (d) Different pigments from an extract of flower petals. (e) Butter from curd. (f) Oil from water. (g) Tea leaves from tea. (h) Iron pins from sand. (i) Wheat grains from husk. (j) Fine mud particles suspended in water.

Identify the solutions among the following mixtures : (a) Soil, (b) Sea water, ( c) Air, (d) Coal and (e) Soda water.

Which of the following materials fall in the category of a pure substance ? (a) Ice, (b) Milk, ( c) Iron, (d) Hydrochloric acid, (e) Calcium oxide, (f) Mercury, (g) Brick, (h) Wood and (i) Air.

Write formulas for the following compounds : (a) Mercury (II) chloride (b) Nickel (II) sulphate ( c) Tin (IV) oxide (d) Thallium (I) sulphate (e) Iron (III) sulphate (f) Chromium (III) oxide

A portein has been isolated as sodium salt with their molecular formula Na_(x)P (this notation means that xNa^(+) ions are associated with a negatively charged protein P^(-x)) . A solution of this salt was prepared by dissolving 0.25g of this sodium slat of protein in 10g of water adn ebulliscopic analysis revealed that soluion boils at temperature 5.93 xx 10^(-3).^(@)C higher than the normal boiling point of pure water. K_(b) of water 0 .52 kg mol^(-1) . Also elemental analysis revealed that the salt contain 1% sodium metal by weight. Deduce molecular formula and determine molecular weight of acidic form of protein H_(X)P .

Surafce tension is exhibited by liquids due to force of attraction between the molecules of the liquid .The surface tension decreases with increases in temperature and vanishes at boiling point Given that the latent heat of vaporization for water L_(v)=540(kcal)/(kg) the mechanical equivalent of heat J=4.2(J)/(cal) density of water rho_(w)=10^(3)kgl^(-1) ,Avogadro'sno. N_(A)=6.0xx10^(26)k " mole"^(-1) . Molecular weight of water M_(A)=10kg , for 1k mole . (a) Estimate the energy required for one molecule of water to evaporated. (b) Show that the inter molecular distance for water is d=((M_(A))/(N_(A))xx(1)/(rho_(w)))^((1)/(3)) and find its value. (c ) 1 g of water in the vapour state at 1 atm occupies 1601cm^(3) , estimate the intermolecular distance at boiling point in the vapour state. (d) During vaporisation a molecule overcomes a force F, assumed constant to go from an inter molecular distance d to d .Estimate the value of F. (e ) Caculate (F)/(d) , which is a measure of the surface tension.

The arrangemen t of orbitals on the basis of energy is based upon th eir (n + Z) value. Lower the value o f (n + Z), low er is th e energy. For o rb itals h aving sam e values of (n + Z), th e o rb ital w ith low er value of n will have lower energy. (I) Based upon the above inform ation, arrange th e fo llo w in g o r b ita ls in th e in c re a s in g order of energy. (a) Is, 2s, 3s, 2p (b) 4s, 3s, 3p, 4d (c) 5p, 4d, 5d, 4f, 6s (d) 5f, 6d, 7s, 7p (II) Based u p o n th e above inform ation, solve the questions given below : (a) W hich of th e following orbitals has the lowest energy ? 4d, 4f, 5s, 5p (b) W hich of the following orbitals has the highest energy ? 5p, 5d, 5f, 6s, 6p