An exergonic reaction proceeds with net release of free energy.
An endergonic reaction absorbs free energy
Answer:
9.39 × 10²² molecules
Explanation:
We can find the moles of gases (n) using the ideal gas equation.
P . V = n . R . T
where,
P is the pressure (standard pressure = 1 atm)
V is the volume
R is the ideal gas constant
T is the absolute temperature (standard temperature = 273.15 K)

There are 6.02 × 10²³ molecules in 1 mol (Avogadro's number). Then,

Answer:
B
Explanation:
This is because exothermic reactions occurs when bnds are formed, and involves the release of energy.
Endothermic reaction occur when bonds are broken,and involves absorption of energy.
I believe it would be the first option. It forms iron oxide (rust) when exposed to moisture and air.
1. Determine if the ionic substances can break apart into ions.
- e.g. CaCO3 isn't very soluble, do it can't dissolve and dissociate. If it can't pop apart, no ions.
2. Swap the partners for all the other ions that you can get from step 1. You can skip pairings with the same charge - a + can't get close to another + to react.
3. Use solubility, acid/base, and redox rules to see if anything will happen with the ions in solution.<span />