Given that AHºrn = - 386.2 kJ for the following, calculate the AHºf for Fe(CO)5 (g). Fe203 (s) + 13 CO (g) = 2 Fe(CO)5 (g) + 3 CO2 (g)

Sally is making a model of a magnesium atom with an atomic mass number of 24 for her chemistry class. she has foam balls for the protons, neutrons, and electrons. she has added 6 neutrons to her model so far. how many more neutrons does she need to add to complete her neutral atom of magnesium?

How many moles is 14.5 cm^3 of platinum? the density of platinum is 21.45 g/cm^3.

Which statement about hf is true? it is zero for any compound in its standard state. it is positive when the bonds of the product store more energy than those of the reactants. it is negative when a compound forms from elements in their standard states. it is zero for any element that is in the liquid state.