ASSIGNMENT IN CHEMISTRY Essay Example | Topics and Well Written Essays - 1000 words

ASSIGNMENT IN CHEMISTRY - Essay Example At that time, the equilibrium mixture was quickly cooled in an ice bath and analyzed where the amount of A remaining was found to be 0.04 moles. b. What was the purpose of the ice bath The ice bath is used to lower the temperature of the mixture. Alcohols and esters are volatile substances and higher temperature will volatilize the said substances and might lead to analytical errors. a. the pressure is increased - According to Le Chatelier, the position of equilibrium will move in such a way as to counteract the change in pressure. That means that the position of equilibrium will move so that the pressure is reduced again. Pressure is caused by gas molecules hitting the sides of their container. The more molecules you have in the container, the higher the pressure will be. The system can reduce the pressure by reacting in such a way as to produce fewer molecules. In this case, there is 1 molecule on the left-hand side of the equation, and 2 on the right. Increasing the pressure on a gas reaction shifts the position of equilibrium towards the side with fewer molecules. In this case towards the reverse reaction. b. the temperature is increased - According to Le Chatelier, the position of equilibrium will move in such a way as to counteract the change. ... Alcohols and esters are volatile substances and higher temperature will volatilize the said substances and might lead to analytical errors. c. Give an expression for the equilibrium constant for the reaction and calculate a numerical value from the data provided. K = [CH3COOCH3] [H2O] / [CH3COOH] [CH3OH] = [.04 moles x 80] [.04 moles x 20] / [.04 moles 64] [.04 moles x 36] = [3.2] [0.8] / [2.56] [1.44] = 0.6944 d. Why is the volume not given (or not important in this instance) Volume is not given because it will not make any significant difference in the concentration of the substances present. 3. When Nitrogen (1 mole) and Hydrogen (3 moles) react at constant temperature at a pressure of 5 x 10 ^6 Pa, the equilibrium mixture was found to contain 0.6 moles of ammonia. a. Calculate mole fractions of all species involved at equilibrium. N2 + 3H2 2 NH3 Mole fraction of N2 = 1- .06 moles = 0.94 / 5.74 = 0.1638 Mole fraction of H2 = 3 (1-.06 moles) = 3.6 / 5.74 = 0.6272 Mole fraction of NH3 = 2 (0.6) = 1.2 / 5.74 = 0.2090 b. Calculate partial pressure of all species involved at equilibrium. Pressure = 5 x 10^6 Pa PN2 = 0.94 RT/V PH2 = 3.6 RT/V PNH3 = 1.2 RT/V c. Calculate Kp = [pNH3]^2 / [pN2] [pH2]^3 4. Gaseous phosphorous(V) Chloride dissociates reversibly as shown below : PCl5 (g) PCl3 (g) + Cl2 (g) H = +ve Use Le Chatelier's Principle to state and explain the effect on the position of the equilibrium when: a. the pressure is increased - According to Le Chatelier, the position of equilibrium will move in such a way as to counteract the change in pressure. That means that the position of equilibrium will move so that the pressure is reduced again. Pressure