Determine the delta H for the following reaction

C3H4(g) + 2H2(g) --> C3H8(g)

delta Hrxn = (n*deltaHproducts) - (n*deltaHreactants)

Look up delta Hf in your text tables.

C3H4(g) + 2H2(g) --> C3H8(g) tentukan prubahan entalpi reaksi

To determine the change in enthalpy (ΔH) for the given reaction, we need to subtract the sum of the enthalpies of the reactants from the sum of the enthalpies of the products.

The balanced equation for the reaction is:
C3H4(g) + 2H2(g) --> C3H8(g)

The standard enthalpy of formation (ΔHf°) is typically used to determine the enthalpy change. We need to know the values for ΔHf° of the compounds involved in the reaction.

ΔHf° for C3H4(g) = 68.3 kJ/mol
ΔHf° for H2(g) = 0 kJ/mol (H2 is a diatomic element in its standard state, so its ΔHf° is taken as zero)
ΔHf° for C3H8(g) = -103.8 kJ/mol

Now, let's calculate ΔH for the reaction by using the given enthalpy values:

ΔH = Σ(ΔHf° of products) - Σ(ΔHf° of reactants)

ΔH = [(-103.8 kJ/mol)] - [(68.3 kJ/mol) + (2 × 0 kJ/mol)]

Simplifying the equation:

ΔH = -103.8 kJ/mol - 68.3 kJ/mol
ΔH = -172.1 kJ/mol

Therefore, the change in enthalpy (ΔH) for the reaction C3H4(g) + 2H2(g) --> C3H8(g) is -172.1 kJ/mol.

To determine the enthalpy change (ΔH) for a reaction, you need to use the bond enthalpies of the compounds involved. Bond enthalpy is the amount of energy required to break a specific bond in a molecule.

Here's how you can calculate ΔH for the given reaction:

1. Determine the bonds broken and formed:
- In the reactants (C3H4 and 2H2), the bonds broken are the C-C bond in C3H4 and the H-H bond in H2.
- In the product (C3H8), the bonds formed are three C-H bonds.

2. Find the bond enthalpies of the bonds:
- The bond enthalpy of a C-C single bond is approximately 348 kJ/mol.
- The bond enthalpy of an H-H bond is approximately 436 kJ/mol.
- The bond enthalpy of a C-H bond is approximately 413 kJ/mol.

3. Calculate the total energy needed to break the bonds:
- There is one C-C bond and two H-H bonds in the reactants, so the energy needed to break these bonds is:
1 * 348 kJ/mol + 2 * 436 kJ/mol = 1220 kJ/mol

4. Calculate the total energy released when the new bonds form:
- In the products, three new C-H bonds are formed, so the energy released is:
3 * 413 kJ/mol = 1239 kJ/mol

5. Calculate ΔH:
- ΔH = Energy required to break bonds - Energy released when bonds form
ΔH = 1220 kJ/mol - 1239 kJ/mol = -19 kJ/mol

The value of -19 kJ/mol represents the enthalpy change (ΔH) for the reaction C3H4(g) + 2H2(g) → C3H8(g). The negative sign indicates that the reaction is exothermic, meaning it releases energy.