if mnso4 → mno+so3 is not a synthesis reaction, then what type of reaction is it?
single-displacement
decomposition
combustion
double-displacement

MnSO₄ → MnO+SO₃ is a decomposition reaction.

Explanation:

In a decomposition reaction, a single substance breaks down or breaks down, producing two or more different substances. In other words, decomposition reactions are those that form two or more substances from a compound. In this reaction the atoms that form a compound are separated to give the products according to the formula:

AB → A + B

This type of reactions can occur spontaneously or caused by certain external factors, such as heat, that promote the breakdown of the molecule into simpler substances.

There are 3 types of decomposition reactions, depending on the external factor that causes the reaction:

Then MnSO₄ → MnO+SO₃ is a decomposition reaction.