What is the name of an ionic compound with a negative oxide ion and a positive iron ion? (Really need this answered asap!)

Achemical reaction is done in the setup shown, resulting in a change of mass. what will happen if the same reaction is done in a sealed container that is placed on the electronic balance?

What is the enthalpy of combustion (per mole) of c4h10 (g)? –2,657.5 kj/mol –5315.0 kj/mol –509.7 kj/mol –254.8 kj/mol

An uncovered pot of water lies out in the sun. which statements correctly describe what happens at the surface of the liquid water? 1. the vapor pressure remains constant regardless of the water temperature. 2. the vapor pressure is produced by water molecules that have evaporated. 3. the vapor pressure increases as the sun heats the water in the pot. 4. evaporation stops once the vapor pressure reaches a certain point. 5. evaporation and condensation both occur on the liquid’s surface.