lab 2 - analysis of vinegar Flashcards
what is the purpose of this lab?
to introduce titrations as a method to analyze the concentration of acetic acid in vinegar
what is titration?
how much of a substance is in a solution by slowly adding a second solution until a reaction is complete
equivalence point
the point at which stoichiometrically equal amounts of acid and based have reacted (chemical equation is balanced)
end point
the observable colour change of the indicator, signalling the point is reaches
what is the product of acetic acid (CH3COOH) in vinegar plus sodium hydroxide (NaOH)
sodium acetate (CH3COONa + H20)
what is the purpose of titration?
to determine the concentration of an unknown analyze using a standard solution of known concentration
why is phenolphthalein used as an indicator in this experiment?
phenolphthalein changes color near the pH of the equivalence point for the reaction between acetic acid and sodium hydroxide
what role does sodium hydroxide play in this experiment?
sodium hydroxide is the titrant (standard solution) used to react with acetic acid in vinegar
what does the 1:1 mole ratio mean?
it changes colour when it is at the equivalence point (the same ratio)
true or false - volume of NaOH is equal to moles of NaOH
true
what is the SDS of sodium hydroxide?
corrosive to metals, skin corrosion, eye damage, aquatic hazard
what is the formula for calculating moles of a substance?
moles = molarity x volume (L)
what is the SDS of acetic acid?
flammable liquids, skin corrosion, eye damage,
what is the SDS of phenolphthalein?
skin irritation, germ cell mutagencity, reproductive toxicity, carionogencity
what is analyte
the solution you are testing. for example testing for sugar in blood. the analyte is sugar
