What is Gibbs free energy? (3.3.4 Quiz: Spontaneity of a Reaction) - The energy contained within the bonds of molecules
- The energy lost as heat to the surrounding molecules
- The energy in the form of kinetic energy in a system
- The useable energy released or absorbed by a reaction (correct answer)

What pressure will be exerted by 0.675 moles of a gas at 25*c if it is in a 0.750-l container?

What does the mass of 0.7891 mol of ferric oxide (fe2o3)

Modern pennies are composed of zinc coated with copper. a student determines the mass of a penny to be 2.482 g and then makes several scratches in the copper coaling (to expose the underlying zinc). the student puts the scratched penny in hydrochloric acid, where the following reaction occurs between the zinc and the hcl (the copper remains undissolved): zn(s) + 2 hcl(aq) → h2(g) + zncl(aq)the student collects the hydrogen produced over water at 25 °c. the collected gas occupies a volume of 0.899 l at a total pressure of 79 j mmhg. calculate the percent zinc (by mass) in the penny. (assume that all the zn in the penny dissolves.)