Unit-9 Chemical Equilibrium
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Unit-9 Chemical Equilibrium
Answer: In the Contact process, SO2 reacts with oxygen to form SO3, which is then used to make sulphuric acid.
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Answer: Decreasing a product concentration makes the forward reaction more favourable, so the equilibrium shifts towards the products.
Answer: In reversible reactions the products can change back into reactants, and equilibrium is established when both rates become equal.
Answer: The formation of ammonia is exothermic, so high temperature favours the reverse endothermic decomposition and reduces the yield.
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Answer: Le Chatelier's principle states that the equilibrium shifts in the direction that opposes or reduces the applied stress.
Answer: Kc is the ratio of the product of concentrations of products (raised to their coefficients) to that of reactants (raised to their coefficients).
Answer: Adding more reactant (H2) shifts the equilibrium towards the forward direction to consume the extra hydrogen.
Answer: The reverse reaction of the Contact process decomposes SO3 back into SO2 and oxygen.
Answer: Continuous removal of the product SO3 shifts the equilibrium towards the forward direction, producing more SO3.
Answer: Temperature changes both the position of equilibrium and the numerical value of Kc, while other factors only affect the position.
Answer: By applying the law of mass action to the forward and reverse reactions at equilibrium, Guldberg and Waage derived the equilibrium constant expression.
Answer: Adding a reactant shifts the equilibrium towards the products, increasing the formation of ammonia without changing Kc.
Answer: A catalyst lowers activation energy and speeds up both directions, so equilibrium is reached more quickly.
Answer: Lower temperature favours the exothermic forward direction, shifting the equilibrium towards more SO3 formation.
Answer: High pressure, removal of the product, and adding reactants all shift the equilibrium forward and increase ammonia production.
Answer: Kc stands for the equilibrium constant expressed in terms of molar concentrations of reactants and products.
Answer: Lowering the temperature favours the exothermic forward direction, so more ammonia is formed.
Answer: In a closed system at equilibrium, the amounts of all species become constant because forward and reverse rates are equal.
Answer: When Kc is much greater than 1, the products dominate and the reaction proceeds almost to completion.
Answer: In the Haber reaction the product side has fewer gas moles (2 vs 4), so increased pressure favours this reaction most.