Answer:
BaCl2-- Barium dichloride✔️, the dash (-) has the problem.
Fe2O3-- Iron(iii)oxide✔️, it's not Iron(ii)oxide.
CsNO2-- it's Cesium nitrogen dioxide✔️, not Cesium nitrate.
Mg(HCO3)2-- Magnesium hydrogen carbonate✔️, not magnesium(II) bicarbonate