How many 1s energy staates are presesnt in one mole of sodium vapour?Are they all filled in normal conditions? How many 3s energy states are present in one mole of sodium vapour?Are they all filled in normal conditions?

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.

Comprehension # 2 Calcium lacate is used in the food and beverage industries. It. Has also been used medicinally for treatment of various allergies, for treatment of muscular leg cramps, and as an antidote for variety of poisons, including lead, arsenicals and carbon tetrachloride. A 0.8274 g sample of anhydrous calcium lactate is found by analysis to contain 0.2732 g of C. 0.0382 g H, 0.1520 g Ca and 0.3640 g O . Each mole of calicum lactate is found to contain one mole of calcium ions. Calcium lactate can be crystallised from water as pentahydrate salt. How many grams of calcium lactate pentahydrate would be recovered from 1 g of anhydrous salt :

Two metallic plate A and B , each of area 5 xx 10^(-4)m^(2) , are placed parallel to each at a separation of 1 cm plate B carries a positive charge of 33.7 xx 10^(-12) C A monocharonatic beam of light , with photoes of energy 5 eV each , starts falling on plate A at t = 0 so that 10^(16) photons fall on it per square meter per second. Assume that one photoelectron is emitted for every 10^(6) incident photons fall on it per square meter per second. Also assume that all the emitted photoelectrons are collected by plate B and the work function of plate A remain constant at the value 2 eV Determine (a) the number of photoelectrons emitted up to i = 10s, (b) the magnitude of the electron field between the plate A and B at i = 10 s, and (c ) the kinetic energy of the most energotic photoelectrons emitted at i = 10 s whenit reaches plate B Negilect the time taken by the photoelectrons to reach plate B Take epsilon_(0) = 8.85 xx 10^(-12)C^(2)N- m^(2)

The potential energy (U) of a body of unit mass moving in a one-dimension force field is given by U=(x^(2)-4x+3) . All units are in S.L

One mole of an ideal gas is heated isobarically from the freezing point to the boiling point of water each under normal pressure . Find out the work done by the gas and the change in its internal energy. The amount of heat involved is 1 kJ.

A question paper consists of two sections having respectively, 3 and 5 questions. The followinng note is given on the paper "it is not necessory to attempt all the questions one questions from each section is compulsory". In how many ways can candidate select the questions?

The electricity bill of Atulbhai's house is more. So Sachin advised him to go for Government's subsidy scheme and put solar panels in his house. By doing so Atulbhai's electricity bill reduces. (1) In the solar panel the solar energy is converted into what form of energy ? (2) How many watts of electricity is produced from a typical solar cell when exposed to the sum ? (3) State the limitations of solar energy.