Steve tries to determine the molarity of a concentrated Sulfuric acid solution when 39.7g of dry powder are dissolved to make 464mL of solution in a volumetric flask.
a.) What are two major errors in this problem?

2h2o2--> 2h2o + o2

this reaction is of the spontaneous decomposition of hydrogen peroxide down into water and oxygen.

add 2 molecules of hydrogen peroxide and 2 molecules of water. since oxygen is naturally diatomic, the total number of atoms of each element is now the same on both sides of the equation so it is balanced.

this may not be entirely correct but let me know.