Which one has the higher enthelpy, the reactent or the product?

  • Thread starter Lion214
  • Start date
  • Tags
    Product
In summary, the reaction 2Cl(g)→Cl2(g) has a change in enthalpy of -243.4 KJ and the product, Cl2(g), has a higher change in enthalpy compared to the reactant, 2Cl(g). This is because the reaction is exothermic, meaning that heat is released from the reaction, resulting in a decrease in enthalpy for the products.
  • #1
Lion214
10
0
2Cl(g)→Cl2(g) ΔH = -243.4 KJ

Which has the higher enthalpy under these conditions, 2 Cl (g) or Cl2 (g)?





At first, I thought they would have the same change in enthalpy, because if I make it a reverse reaction, their magnitude will be the same. Then I realized that the signs would reverse, making the change of enthalpy for the product positive. Apparently that was not the answer, as 2 Cl(g) has a higher change in enthalpy. I'm posting this because I want to know why that is?
 
Physics news on Phys.org
  • #2
Think in terms of the exo- and endothermic reaction. Where does the reaction heat come from?
 

Related to Which one has the higher enthelpy, the reactent or the product?

1. What is enthalpy?

Enthalpy is a measure of the total energy of a system, including both its internal energy and the energy required to overcome any external forces, such as pressure or volume changes.

2. How is enthalpy related to chemical reactions?

In a chemical reaction, the enthalpy change is equal to the difference between the enthalpy of the products and the enthalpy of the reactants. This is known as the enthalpy of reaction.

3. Which one has a higher enthalpy, the reactant or the product?

The answer depends on the specific reaction. In an exothermic reaction, the products have a lower enthalpy than the reactants, meaning the reactants have a higher enthalpy. In an endothermic reaction, the products have a higher enthalpy than the reactants, meaning the products have a higher enthalpy.

4. How can we determine the enthalpy change of a reaction?

The enthalpy change of a reaction can be determined experimentally by measuring the heat released or absorbed during the reaction. It can also be calculated using the enthalpy of formation values for each reactant and product.

5. What units are used to measure enthalpy?

The SI unit for enthalpy is joules (J). However, it is often measured in kilojoules (kJ) for convenience in chemical reactions.

Similar threads

Chemistry Valence Bond Theory: Energy of a system with H and Cl atoms
    • Biology and Chemistry Homework Help
Replies
6
Views
2K
Chemistry Why does a negative ΔH indicate an exothermic reaction?
    • Biology and Chemistry Homework Help
Replies
2
Views
2K
Chemistry Question about the Butler-Volmer equation in electrochemistry
    • Biology and Chemistry Homework Help
Replies
1
Views
1K
Enthalpy Question: H2 (g) + Cl2 (g) --> 2 HCl (g) + 184.62 kJ
    • Biology and Chemistry Homework Help
Replies
1
Views
2K
Enthelpy of reaction calculation?
    • Biology and Chemistry Homework Help
Replies
6
Views
13K
Enthelpy change of a neutralisation reaction
    • Biology and Chemistry Homework Help
Replies
3
Views
2K
Standard enthelpy of formation water
    • Biology and Chemistry Homework Help
Replies
10
Views
7K
Chemistry Creating KF Molecule from Neutral Atoms: A Process of Ionization and Binding
    • Biology and Chemistry Homework Help
Replies
2
Views
1K
Enthalpy Calculation for 4B+3O2-->2B2O3 Reaction Using Hess's Law
    • Biology and Chemistry Homework Help
Replies
1
Views
26K
Constructing a balanced equation for KClO3+H2SO4
    • Biology and Chemistry Homework Help
Replies
6
Views
4K

Hot Threads

Recent Insights

Back
Top