Soul of Chemistry

  Solutions of Gateway Examinations to  IISER, NISER, JEE, NEET,   NDA, ICAR, OUAT Topic: Solution (NDA, ICAR, OUAT Level) 1. Solubility of a gas in a solvent varies directly with the prssure of the gas, inversly with the temperature of the solution and directly with the liquefiability of a gas. So all of the above are true. 2.  Calculate the amount of urea dissolved per litre if its aqueous solution is isotonic with 10% cane sugar solution. Isotonic Solutions are those having equal osmotic pressure (O.P). O.P = w R T / m V In case of Urea, w1 = ?, m1 = 60, V1 = 1 litre In case of Cane sugar, w2 = 10g, m2 = 342, V2 = 100ml = 0.1 litre Thus w1 R T / m1 V1 = w2 R T / m2 V2 Or w1 / m1 V1 = w2 / m2 .V2 Thus w1 = 17.543 g = 17.6 g 3.  If we prepare separate solutions of 2 mole urea and 2 moles NaCl in one litre water, then whose boiling point will be higher? Number of particles in NaCl solution will be greater due to ionisation hence the value of any colligative properties will be higher

States of Matter: Gateway to JEE (Main), NEET, ICAR, OUAT and All Similar Entrance Examinations      You need to be friendly with concepts and problems, before appearing any entrance examinations. A systematic flow of concepts and corresponding problems will build your confidence to crack entrance examinations. This gateway will help you rise step wise to reach and crack the entrance examinations. Pratap Sir's Core Concept of States of matter (PSCC: 1): Ideal Gas Equation This equation though applicable to hypothetical ideal gasses, it can be applied to real atmospheric gasses like oxygen, nitrogen, methane etc with little to no error at particular conditions like high temperature and low pressure.     This equation contains all gaseous variables like pressure, temperature, volume and number of moles, given by the formula:  PV = nRT = (w/m) RT ........ eq. 1 where n =  number of moles = given mass (w) / molecular mass (m) .  R = Universal gas constant,  the value of which  depends