Explain the molecular origin of Raoult’s law and Henry’s law.
Raoult's Law ::
Molecular origin of Raoult's law is the effect of the solute on the entropy of the solution. In the pure solvent, the molecules have a certain disorder & a corresponding entropy.Because the entropy of the solution is higher than the pure solvent, the solution has a lower tendency to acquire an even high entropy by the solvent vaporising. In other words, the vapour pressure of the solvent in the solution is lower than that of the pure solvent.
Henry's Law::
In a very dilute solution, a solute molecule will (with rare exceptions) have only solvent molecules as near neighbours, and the probability of escape of a particular solute molecule into the gas phase is expected to be independent of the total concentration of solute molecules. In this case the rate of escape of solute molecules will be proportional to their concentration in the solution, and solute will accumulate in the gas until the return rate is equal to the rate of escape. With a very dilute gas this return rate will be proportional to the partial pressure of solute. Thus, we expect that, for a solution very dilute in solute, in equilibrium with a gas at very low pressure, the gas pressure will be proportional to the amount of dissolved gas—the relation known as Henry’s law.
Explain how Raoult’s law and Henry’s law are used to specify the chemical potential of a component of a mixture.
2. Find and discuss the assumptions of Raoult’s law, modified Raoult’s law and Henry’s law based on the concept that your learned about the fugacity and activity coefficient.
Using Raoult’s law or Henry’s law for each substance (whichever one you think appropriate), calculate the pressure and gas-phase composition (mole fractions) in a system containing a liquid that is 0.3 mole% N2 and 99.7 mole% water in equilibrium with nitrogen gas and water vapor at 80°C.
1- At 25 oC the Henry’s Law constant for carbon dioxide (CO2) dissolved in water is 3.3 x 10-2 mol/L atm. Calculate the solubility of CO2 if the partial pressure of carbon dioxide gas inside a bottle of Fizzy Cola Drink is 6 atm at 25 C 2- Using Raoult’s Law, calculate vapor pressure lowering, DP = C · Po, when 14.0 mL of glycerol (C3H8O3) is added to 496.0 mL of water at 50.0 C. The density of glycerol...
1. What statement is true about Henry’s Law A. The concentration of a gas dissolved in a liquid is directly proportional to the concentration of the gas over the liquid. B. The Henry’s law constant for every gas is the same as long as it dissociates completely. C. Henry’s law is used to determine how dissolved salts change the vapor pressure over a liquid in a sealed container. D. The partial pressure of an individual gas over a liquid is...
Determine the Henry’s law constant for ammonia in water at 25 ºC if an ammoniapressure of 0.022 atm produces a solution with a concentration of 1.3 M.
According to the National Institute of Standards webbook, the Henry’s Law constant for N2 gas is 0.0060 mol/kg⋅bar at 35°C What is the Henry's law constant in units of mol/kg⋅mmHg? (1 bar = 0.9869 atm; 1 atm = 760 mmHg)
Henry’s law states that the solubility of a gas is directly proportional to the partial pressure of the gas if the temperature is constant. Hyperbaric chambers, which provide high pressures (up to 6 atm) of either air or pure oxygen, are used to treat a variety of conditions, ranging from decompression sickness in deep-sea divers to carbon monoxide poisoning. Look up the Henry’s Law Constant (kH) for N2, O2, and CO2 in the textbook. a) Calculate the solubility (concentration in...
2. Raoult’s law is defined as follows: Partial Pressure = Vapor Pressure • Mole fraction This equation predicts… A. How well a salt dissolves in a liquid B. How much higher the partial pressure will be when a salt is dissolved in a liquid C. How much lower the partial pressure will be when a salt is dissolved in a liquid D. How much higher the vapor pressure of a liquid becomes when it enters a phase transition.
1. The Henry’s Law constant for O2 is 770 L atm mol-1 at 25 °C. What mass of oxygen would be dissolved in a 40-L aquarium at 25 °C, assuming an atmospheric pressure of 1.00 atm, and that the partial pressure of O2 is 0.21 atm? 2.The carbon dioxide concentration in a bottle of club soda is 0.12 mol L-1 at 25 °C. What is the pressure of carbon dioxide in the headspace? The Henry’s Law constant for CO2 at...