LE CHATELIER'S PRINCIPLES ASSIGNMENT 1. Continuous removal of one of the products of a chemical reaction has the effect of causing the reaction to go to completion. Explain this in terms of Le Chatelier's principle, using suitable examples. 2. Explain how each of the following factors affects the amount of oxygen gas present in an equilibrium mixture in the following reaction: 4 HCI +0,2 ** 2 H,0 +2 C1 + 114.4 kJ a) raising the temperature of the mixture b) introducing more steam c) increasing the pressure d) addition of a catalyst e) decreasing the volume 3. In both the ammonia, NH, synthesis and the production of So, according to ... Naw + 3 H., 2 NH AH = -92 kJ 2 50.. + 0, 2 50 AH=-180 kJ The mole fraction at equilibrium of the desired product (NH), and SO), is greater at lower temperatures. Despite this, in the commercial production of these substances relatively high temperatures are used. Explain why this is so 4. Define equilibrium in terms of ... a) reaction rates b) changes in observable properties c) energy /enthalpy changes 5. Arsenic can be extracted from its ores by first reacting the ore with oxygen, (called roasting), to form solid As.. which is then reduced using carbon As.O.(s) +6C(s) As.(g) + 6 CO(8) Predict the direction of the shift of the equilibrium position in response to each of the following changes in conditions: a) removal of CO(g) b) addition of arsenic (III) oxide, As.. e) an increase in the volume of the container 6. A land-based vehicle will be an important part of any future exploration of the planet Mars. One proposed design for a Mars rover uses a methane gas fuel cell as its power supply. The methane fuel can be made on Mars using a chemical reaction that has been known for over 100 years - the Sabatier methanation reaction: Cg +4 Hao CH + 2 HOe AH-165 kJ at 250C Predict, using Le Chatelier's principle, the conditions required in a closed Sabatier reactor to produce the maximum amount of methane. 7. In caves we sometimes see large structures known as stalactites and stalagmites. These formations are made of crystals of the insoluble compound calcium carbonate, CaCO, also known as limestone. Calcium carbonate forms when dissolved carbon dioxide and calcium ions combine, according to the following equilibrium: Caco.. + 2H C+H,0 + CO2 Use Le Chatelier's principle to answer the following: a) How would the stalagmites and stalactites be affected if the water in the cave became more acidic? b) How would the hardness of the water (Ca") affect the growth of stalagmites and stalactites