[global]

I'm not a student, but I am a total noob, so I don't know if I have provided enough information to solve this equation:

MgO + NaHSO4 + 5H2O-->

The first ingredient is magnesium oxide, and the second is sodium bisulfate - but I suspect you knew that. : ) The reaction occurs at room temperature, and the water is just enough to make it a thick paste.

[zhyx00]

HSO4=H+ + SO4 2-
MgO+2H+=Mg2++H2O
If water is just enough, then Mg2 + SO4 2- = MgSO4
MgO is basic oxide which can react with H+.