Aqueous and gaseous elements and compounds?

So if a reaction changes the amount of that state, it will typically have a positive molar entropy change. In summary, the sign of ΔS(sys) for the given reactions is positive due to the change in states from more ordered to less ordered, resulting in an increase in entropy. When evaluating reactions like these, only the number of moles of solid, aqueous, and gaseous elements and compounds are counted.
  • #1
lha08
164
0

Homework Statement


Predict the sign of ΔS(sys) for each of the following processes:
a) Zn(s)+2HCl(aq)-->H2(g)+ZnCl2(aq)
b) CH3CH2CH3(g)+5O2(g)-->3CO2(g)+4H2O(l)

Also, I'm not sure but when we're evaluating questions like these, do we count the number of moles only of solids, aqueous and gaseous elements and compounds?


Homework Equations





The Attempt at a Solution


The first one, ΔS is POSITIVE but I'm not sure why though because 3 moles reactants-->2 moles reactant (should be more ordered (negative)...) thanks.
 
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  • #2


lha08 said:
Zn(s)+2HCl(aq)-->H2(g)+ZnCl2(aq)
The states are changing from more ordered ones (solid) to less ordered ones (gas) overall. This is an increase in entropy.
Hope that helps, I'm pretty confident its right.
 
  • #3


Out of solids, liquids, and gases, one state typically has a very large molar entropy that dominates over the others.
 

Related to Aqueous and gaseous elements and compounds?

1. What is the difference between aqueous and gaseous elements and compounds?

Aqueous elements and compounds are those that are dissolved in water, while gaseous elements and compounds are those that exist in a gaseous state at standard temperature and pressure.

2. Can you give examples of aqueous and gaseous elements and compounds?

Examples of aqueous elements and compounds include sodium chloride (table salt) and carbon dioxide (CO2). Examples of gaseous elements and compounds include oxygen (O2) and nitrogen (N2).

3. How do aqueous and gaseous elements and compounds interact with each other?

Aqueous and gaseous elements and compounds can react with each other through various chemical reactions. For example, when aqueous sodium hydroxide (NaOH) is mixed with gaseous hydrogen chloride (HCl), it forms a salt (NaCl) and water (H2O).

4. What properties make an element or compound more likely to be aqueous or gaseous?

The polarity of a molecule is a major factor in determining whether it will be aqueous or gaseous. Polar molecules are more likely to be aqueous, while nonpolar molecules are more likely to be gaseous. Additionally, the boiling point of a substance also plays a role, as those with lower boiling points are more likely to exist as gases.

5. Are there any elements that can exist in both aqueous and gaseous states?

Yes, there are elements that can exist in both aqueous and gaseous states depending on their conditions. For example, water (H2O) can exist as a gas (water vapor) at high temperatures and as a liquid at room temperature. Carbon dioxide (CO2) can also exist as a gas in the atmosphere and as an aqueous solution when dissolved in water.

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