Calculate the change in enthalpy (LaTeX: \DeltaΔH) of a reaction with the following information:

Energy of Reactants = 129 kJ

Energy of the Products = 110 kJ

Energy of the Transition State = 198 kJ

-19 kJ

Explanation:

The change in enthalpy is mathematically expressed as the difference between the the total potential energy of products and the potential energy of the reactants :

Where:

Then:

The negative sign in this result means we have a negative enthalpy, hence an exothermic reaction (where heat is released).

1. 1 mole of anything contains 6.022x10^23 pieces  

d  

2. a  

3. c, number  

5. 1.24x10^24atoms / 6.022x10^23atoms/mole = 2moles h2 atoms  

6. fe2br3 mass = 2moles x mass fe + 3 moles x mass br  

molar mass = grams / number of moles = g/mole  

to find moles = g / molar mass  

to find mass = g = molar mass / moles