Help me with synthesis of aspirin lab related questions please.

1. How do you clean up a spill of concentrated phosphoric acid?
a. add solid citric acid to neutralize and then wash the residue down the drain
b. add solid sodium bicarbonate to neutralize and then wash the residue down the drain
c. add solid sodium hydroxide to neutralize and then wash the residue down the drain
d. add aqueous sodium hydroxide to neutralize and then wash the residue down the drain


2. What are the hazards associated with acetic anhydride?
a. corrosive
b. flammable
c. irritating to the eyes and skin
d. all of the above


3. When using vacuum filtration which type of tubing is best?
a. thin walled tubing
b. think walled tubing


4. What happens when PO4H3 is heated? Write out the complete equation please.

1. a
2. b
3. a
4. it dissociates into [PO4]3- and 3H+