Explanation:
Before proceeding to answering the question, we have t understand what we mean by both mixture and compound.
A mixture is the physical combination of two or more substances in which the identities are retained and are mixed in the form of solutions, suspensions and colloids.
A compound on the other hand is a chemical substance composed of many identical molecules composed of atoms from more than one element held together by chemical bonds.
The two other reason why H2SO4 is a compound and not a mixture are;
1) The components which are Hydrogen, Sulphur and Oxygen cannot be separated by physical means.
2) It has a constant melting and boiling point.