Consider the following reversible reaction:Initial concentrations:CH3-CH2-OH) = 1 mol.dm-3(CH3-COOH)= 1 mol.dm-3(CH3-CH2-O-CO-CH3)= 0 mol.dm-3(H2O)= 0 mol.dm-3Equilibrium concentrations:(CH3-CH2-OH) = 0.33mol.dm-3(CH3-COOH)= 0.33 mol.dm-3(CH3-CH2-O-CO-CH3)= 0.66 mol.dm-3(H2O)= 0.66 mol.dm-3Kc= 4 at temperature 100 CWhat are the new equilibrium concentrations of all species if 1 mol.dm-3 of CH3-CH2-OH and CH3-COOH are added to this equilibrium mixture? (Apply Le-Chatelier's principle)(Temperature and Kc remain constant)
Correct answer: C. (CH3-COOH)= 0.666 mol.dm-3(CH3-CH2-OH) = 0.666 mol.dm-3(CH3-CH2-O-CO-CH3)= 1.333 mol.dm-3(H2O)= 1.333 mol.dm-3
- A. (CH3-COOH)= 0.333 mol.dm-3(CH3-CH2-OH) = 1.333mol.dm-3(CH3-CH2-O-CO-CH3)= 1.666 mol.dm-3(H2O)= 1.666 mol.dm-3
- B. (CH3-COOH)= 1.333 mol.dm-3(CH3-CH2-OH) = 0.333mol.dm-3(CH3-CH2-O-CO-CH3)= 0.666 mol.dm-3(H2O)= 0.666 mol.dm-3
- C. (CH3-COOH)= 0.666 mol.dm-3(CH3-CH2-OH) = 0.666 mol.dm-3(CH3-CH2-O-CO-CH3)= 1.333 mol.dm-3(H2O)= 1.333 mol.dm-3
- D. (CH3-COOH)= 0.333 mol.dm-3(CH3-CH2-OH) = 0.333mol.dm-3(CH3-CH2-O-CO-CH3)= 1.333 mol.dm-3(H2O)= 1.333 mol.dm-3
Explanation
Change in concentration of of CH3COOH is 1-0.33 = 0.66 mol.dm-3Change in concentration of of CH3CH2OH is also 1-0.33 = 0.66 mol.dm-3Where as change in conc of CH3CH2OCOCH3 is 1 + 0.333 = 1.333 moldm-3And change in conc for H2O is also 1 + 0.333 = 1.333 mol.dm-3
Last updated
About Le Chatelier's Principle
Le Chatelier's principle predicts how an equilibrium responds when concentration, pressure or temperature changes. Questions apply it to reversible reactions, identify the direction of shift and distinguish genuine equilibrium changes from the effect of a catalyst, which changes the rate of reaching equilibrium but not its position.
Practise Chemical Equilibrium
625 free Chemical Equilibrium MCQs from Chemistry, each with the correct answer and an explanation. Unlimited attempts, no account needed.
Exams that ask Chemistry questions like this
Chemistry is on 12 papers prepared for on TestUstad, and all of them draw the same bank, so this question is worth knowing for every one of them.
Related questions
A chemical engineer wants to use the Haber process in order to produce ammonia as raw material for fertilizers. Which of the following parameters must the chemical engineer AVOID in order to obtain the maximum yield of ammonia?N2(g) + 3H2(g) -> 2NH3(g) ΔH0 = -92.6 kJ/mol
Adding a catalyst to a system at equilibrium
An exothermic reaction is allowed to reach equilibrium; if heat energy is then removed, the equilibrium will shift
By decreasing the pressure the reaction will go to that direction where_________________?
Change in pressure will only affect the substance which are in: