CHEMISTRY PLEASE HELP
posted by Josh on .
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?
a)Here are the equations used for the standardization of NaoH>
1. moles KHP = grams/molar mass
2. moles NaOH = moles KHP
3. M NaOH = moles NaOH/L NaOH
If KHP is spilled that means grams is too small in equn 1 which makes moles small; eqn 2 makes moles NaOH too small, #3 makes M NaOH too small.
1. moles NaOH = L x M
2. moles NaOH = moles unknown acid
3. molar mass = grams/moles acid
If some of the acid were not titrataed, then eqn 1 gives L too small which makes moles NaOH too small. Eqn 2 means moles unk acid too small. Eqn 3 means molar mass too large.
1. L x M = moles NaOH
2. moles vinegar = moles NaoH
3. L x M = concn vinegar.
Volume in pipet blown out means L equn 1 too large, that makes moles vinegar and moles NaOH too large (equn 2). and eqn 3 makes concn vinegar too large.
d)refer to equations in c.
Air bubble appears in buret tip (but remains in the tip) means extra NaOH must be added so volume is too large frm equn 1 so moles NaOH too large, equn 2 means vinegar too high, and equn 3 means concn vinegar too high.
1) What effect would each of the errors described below have on the concentration of potassium hydrogenphthalate?