In: Chemistry
Predict the change in pH when sodium lactate is added to a solution of lactic acid.
Increase
Decrease
Stay the same
Answer :
pH will increase.
Explanation :
Lactic acid <==> H+ + Lactate ion
Equilibrium is maintained in only lactic acid solution.
When sodium lactate is added into the Solution, backward reaction proceed according to Le-chatelier's principle because if we increase concentration of any of product ( here lactate) than equilibrium will shift in that direction where its effect can be reduced which is in backward direction. So, concentration of H+ will decrease and pH will increase.
pH = - log (H+)
Or
Lactate will combine with H+ already dissociated in lactic acid solution and form lactic acid . Due to which concentration of H+ will decrease in the solution which means Solution become less acidic . So, pH will increase .
High pH means basic Solution and low pH means acidic solution.