a highly toxic gas called phosgene is produced by the reaction CO(g)+Cl2(g)-->COCl2(g), triangleH=-108 kJ/mol.
how would increasing the temperature affect the amount of COCl2 formed? Explain.
how would increasing the temperature affect the rate of the reaction? Explain
2 answers
surely by now, you have learned that ∆ is pronounced "delta" not "triangle"
CO(g)+Cl2(g)-->COCl2(g), delta H = -108 kJ/mol.
A negative delta H means the reaction is exothermic so let me rewrite the equation as CO(g) + Cl2(g) --> COCl2(g) + heat
This question is one about Le Chatelier's Principle. Le Chatelier's Principle states that "when a system in equilibrium is subjected to a stress, the reaction will shift is such a way as to relieve the stress". Many students just don't understand that. A shorter and much less esoteric (but just as accurate) statement is "A system at equilibrium will undo what we do to it". Therefore, if we INCREASE the temperature (ADD HEAT), the system will react to REMOVE the heat. How can it do that. It COULD move to the right which will produce more COCl2 and more heat. That isn't what you want. OR it COULD move to the left. If it does that COCl2 + heat produces more of the CO and Cl2. That way the system is using up the heat we've added. That's what it does. So the correct answer is that the reaction will shift to the left using up COCl2 (along with some of the added heat) and producing more of the starting materials of CO and Cl2.
As for the second question, increasing T increases the mobility of the reactants so they interact more frequently which increases the rate of the reaction.
A negative delta H means the reaction is exothermic so let me rewrite the equation as CO(g) + Cl2(g) --> COCl2(g) + heat
This question is one about Le Chatelier's Principle. Le Chatelier's Principle states that "when a system in equilibrium is subjected to a stress, the reaction will shift is such a way as to relieve the stress". Many students just don't understand that. A shorter and much less esoteric (but just as accurate) statement is "A system at equilibrium will undo what we do to it". Therefore, if we INCREASE the temperature (ADD HEAT), the system will react to REMOVE the heat. How can it do that. It COULD move to the right which will produce more COCl2 and more heat. That isn't what you want. OR it COULD move to the left. If it does that COCl2 + heat produces more of the CO and Cl2. That way the system is using up the heat we've added. That's what it does. So the correct answer is that the reaction will shift to the left using up COCl2 (along with some of the added heat) and producing more of the starting materials of CO and Cl2.
As for the second question, increasing T increases the mobility of the reactants so they interact more frequently which increases the rate of the reaction.
1 answer