What mass of compound must be weighed out to have a 0.0223 mol sample of h2c2o4 (m=90.04 g/mol)?

Mass of  H2C2O4 :

mm = 90.04 g/mol

number of moles : 0.0223 moles

m = n * mm

m = 0.0223 * 90.04

m = 2.007 g 

hope this helps!.

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.