Give the structure of product obtained when ethyl phenylacetate (PhCH2COOEt) is treated with each of the following esters under the conditions of the mixed Claisen condensation: (a) diethyl carbonate, (b) diethyl oxalate, and (c) ethyl formate.

Aphysical change is one that you can put in and remove like a ham sandwich. the stuff you put in there can be changem its not permanet. a chemical change is on that can't be change thats permanet. like when you make a cake and bake it. you can't get those ingredients back.

The air is going to come out because of the low pressure.