Acid-Base Titrations
a) How will the concentration of NaOH be affected if during the titration some of the solid potassium hydrogen phthalate was spilled during the transfer? Will the concentration of the standardized NaOH increase, decrease, or have no effect?
b) How will the molar mass of an unknown acid be affected if some of the solid remained after the titration was complete? Will the concentration of the molar increase, decrease, or have no effect?
c) How will the concentration of acetic acid in vinegar be affected if the liquid retained in the pipet is blown out? Will the concentration of acetic acid in vinegar increase, decrease, or have no effect?
d) How will the concentration of acetic acid in vinegar be affected if during the titration an air bubble appears in the tip of the buret? Will the concentration increase, decrease, or have no effect?
Look at how you calculated the M of the NaOH.
You had KHP and moles= grams/molar mass.
Then M NaOH = moles/L
So if some of the KHP was spilled, that means grams was too low, which makes moles too low and if moles is too low when plugged into M NaOH, then moles/L will be too low and M will be too low.
The others are done with the same kind of reasoning.
KHP?
C and D are worded extremely poor.
a) If some of the solid potassium hydrogen phthalate (KHP) is spilled during the transfer in an acid-base titration, there will be less KHP available to react with the NaOH. As a result, less NaOH will be consumed during the titration. Since the concentration of NaOH is calculated based on the amount consumed during titration, having less consumption will lead to an overestimated concentration of NaOH. Therefore, the concentration of the standardized NaOH will appear higher than it actually is.
b) If some of the solid acid remains after the titration is complete, it means that not all of the acid reacted with the base. As a result, the calculated molar mass of the unknown acid will be underestimated. The molar mass is determined by stoichiometry and the volume of base required to neutralize a known mass of the acid. If some of the acid is left unreacted, the calculated molar mass will be lower than the actual molar mass of the acid.
c) If the liquid retained in the pipet is blown out, a portion of the acetic acid in the vinegar will be lost. The concentration of acetic acid in vinegar is determined by the ratio of acetic acid to the total volume of vinegar. By blowing out the liquid in the pipet, the total volume is decreased, but the amount of acetic acid remains the same. Therefore, the concentration of acetic acid in vinegar will increase because there is a smaller volume of vinegar with the same amount of acetic acid.
d) If an air bubble appears in the tip of the buret during the titration, it will affect the accuracy of the results. The concentration of acetic acid in vinegar will be underestimated. This is because the volume of acetic acid solution delivered by the buret will be less than intended due to the presence of the air bubble. As a result, less NaOH will be consumed to neutralize the acetic acid, leading to an underestimated concentration of acetic acid in the vinegar.