Name: Rhiannon S.
I have the weight of acetic anhydride needed for a
reaction in grams and moles. I need to work out how many ml I need. Can
I do this without knowing the concentration of the acetic anhydride?
Yes. Use the relationship for density: d = m / V. Look up the density of
acetic anhydride in the chemical handbook. Acetic anhydride (AA) as delivered
from the chemical supply company is essentially pure, not dissolved in any
solvent. Therefore its concentration is 100 %.
Solve the above relationship for the Volume, namely V = m / d. Divide the mass
(grams) you need by the density in g/mL and you will have the volume in mL
required for your experiment.
Use caution when handling acetic anhydride. It reacts violently with water to
generate heat and acetic acid. Be sure the measuring cylinder is bone dry
before you pour the AA into it.
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Update: June 2012