Discover a wealth of information and get your questions answered on IDNLearn.com. Whether it's a simple query or a complex problem, our experts have the answers you need.
Sagot :
To determine the enthalpy change of a reaction ([tex]\( \Delta H_{\text{rxn}} \)[/tex]), we need the balanced chemical equation for the reaction and the standard enthalpies of formation ([tex]\( \Delta H_f^\circ \)[/tex]) for the reactants and products. Unfortunately, your question does not provide the balanced chemical equation. However, I can explain the general steps to calculate the enthalpy change of a reaction using the standard enthalpies of formation.
Step-by-Step Solution:
1. Write the Balanced Chemical Equation:
- The first step is to write the balanced equation for the reaction. For example, consider a hypothetical reaction:
[tex]\[ aA + bB \rightarrow cC + dD \][/tex]
2. Identify the Standard Enthalpies of Formation:
- From the provided table, identify the [tex]\( \Delta H_f^\circ \)[/tex] values for each reactant (A, B) and product (C, D).
3. Calculate the Enthalpy Change for Reactants and Products:
- Multiply the standard enthalpy of formation of each reactant and product by their respective coefficients from the balanced chemical equation.
[tex]\[ \Delta H_{\text{reactants}} = a \Delta H_f^\circ(A) + b \Delta H_f^\circ(B) \][/tex]
[tex]\[ \Delta H_{\text{products}} = c \Delta H_f^\circ(C) + d \Delta H_f^\circ(D) \][/tex]
4. Apply Hess's Law to Calculate the Reaction Enthalpy:
- Use the relation:
[tex]\[ \Delta H_{\text{rxn}} = \Delta H_{\text{products}} - \Delta H_{\text{reactants}} \][/tex]
Example Calculation:
Given the table values:
- [tex]\( \Delta H_f^\circ(C_2H_2(g)) = -26.7 \text{ kJ/mol} \)[/tex]
- [tex]\( \Delta H_f^\circ(NH_3(g)) = -46.19 \text{ kJ/mol} \)[/tex]
- [tex]\( \Delta H_f^\circ(HBr(g)) = 236.23 \text{ kJ/mol} \)[/tex]
- [tex]\( \Delta H_f^\circ(HCl(g)) = -92.30 \text{ kJ/mol} \)[/tex]
- [tex]\( \Delta H_f^\circ(HF(g)) = -268.6 \text{ kJ/mol} \)[/tex]
- [tex]\( \Delta H_f^\circ(HI(g)) = 25.9 \text{ kJ/mol} \)[/tex]
- [tex]\( \Delta H_f^\circ(NaCl(s)) = -411.0 \text{ kJ/mol} \)[/tex]
Let's assume we have a balanced chemical equation (hypothetical example):
[tex]\[ 2 HCl(g) + Na_2O(s) \rightarrow 2 NaCl(s) + H_2O(g) \][/tex]
- Identify [tex]\( \Delta H_f^\circ \)[/tex] for each component from the table:
- [tex]\( HCl(g) \)[/tex]: [tex]\( -92.30 \text{ kJ/mol} \)[/tex]
- [tex]\( NaCl(s) \)[/tex]: [tex]\( -411.0 \text{ kJ/mol} \)[/tex]
- As [tex]\( Na_2O(s) \)[/tex] and [tex]\( H_2O(g) \)[/tex] are not provided, we'll use hypothetical values:
- [tex]\( Na_2O(s) \)[/tex]: [tex]\( -256.7 \text{ kJ/mol} \)[/tex]
- [tex]\( H_2O(g) \)[/tex]: [tex]\( -241.8 \text{ kJ/mol} \)[/tex]
- Calculate the total enthalpy for reactants:
[tex]\[ \Delta H_{\text{reactants}} = 2 \cdot (-92.30) + (-256.7) = -184.6 - 256.7 = -441.3 \text{ kJ/mol} \][/tex]
- Calculate the total enthalpy for products:
[tex]\[ \Delta H_{\text{products}} = 2 \cdot (-411.0) + (-241.8) = -822.0 - 241.8 = -1063.8 \text{ kJ/mol} \][/tex]
- Apply Hess's Law:
[tex]\[ \Delta H_{\text{rxn}} = \Delta H_{\text{products}} - \Delta H_{\text{reactants}} = -1063.8 \text{ kJ/mol} - (-441.3 \text{ kJ/mol}) = -1063.8 + 441.3 = -622.5 \text{ kJ/mol} \][/tex]
This is an illustrative example; the actual calculation would depend entirely on the correct balanced chemical equation and the provided data.
Step-by-Step Solution:
1. Write the Balanced Chemical Equation:
- The first step is to write the balanced equation for the reaction. For example, consider a hypothetical reaction:
[tex]\[ aA + bB \rightarrow cC + dD \][/tex]
2. Identify the Standard Enthalpies of Formation:
- From the provided table, identify the [tex]\( \Delta H_f^\circ \)[/tex] values for each reactant (A, B) and product (C, D).
3. Calculate the Enthalpy Change for Reactants and Products:
- Multiply the standard enthalpy of formation of each reactant and product by their respective coefficients from the balanced chemical equation.
[tex]\[ \Delta H_{\text{reactants}} = a \Delta H_f^\circ(A) + b \Delta H_f^\circ(B) \][/tex]
[tex]\[ \Delta H_{\text{products}} = c \Delta H_f^\circ(C) + d \Delta H_f^\circ(D) \][/tex]
4. Apply Hess's Law to Calculate the Reaction Enthalpy:
- Use the relation:
[tex]\[ \Delta H_{\text{rxn}} = \Delta H_{\text{products}} - \Delta H_{\text{reactants}} \][/tex]
Example Calculation:
Given the table values:
- [tex]\( \Delta H_f^\circ(C_2H_2(g)) = -26.7 \text{ kJ/mol} \)[/tex]
- [tex]\( \Delta H_f^\circ(NH_3(g)) = -46.19 \text{ kJ/mol} \)[/tex]
- [tex]\( \Delta H_f^\circ(HBr(g)) = 236.23 \text{ kJ/mol} \)[/tex]
- [tex]\( \Delta H_f^\circ(HCl(g)) = -92.30 \text{ kJ/mol} \)[/tex]
- [tex]\( \Delta H_f^\circ(HF(g)) = -268.6 \text{ kJ/mol} \)[/tex]
- [tex]\( \Delta H_f^\circ(HI(g)) = 25.9 \text{ kJ/mol} \)[/tex]
- [tex]\( \Delta H_f^\circ(NaCl(s)) = -411.0 \text{ kJ/mol} \)[/tex]
Let's assume we have a balanced chemical equation (hypothetical example):
[tex]\[ 2 HCl(g) + Na_2O(s) \rightarrow 2 NaCl(s) + H_2O(g) \][/tex]
- Identify [tex]\( \Delta H_f^\circ \)[/tex] for each component from the table:
- [tex]\( HCl(g) \)[/tex]: [tex]\( -92.30 \text{ kJ/mol} \)[/tex]
- [tex]\( NaCl(s) \)[/tex]: [tex]\( -411.0 \text{ kJ/mol} \)[/tex]
- As [tex]\( Na_2O(s) \)[/tex] and [tex]\( H_2O(g) \)[/tex] are not provided, we'll use hypothetical values:
- [tex]\( Na_2O(s) \)[/tex]: [tex]\( -256.7 \text{ kJ/mol} \)[/tex]
- [tex]\( H_2O(g) \)[/tex]: [tex]\( -241.8 \text{ kJ/mol} \)[/tex]
- Calculate the total enthalpy for reactants:
[tex]\[ \Delta H_{\text{reactants}} = 2 \cdot (-92.30) + (-256.7) = -184.6 - 256.7 = -441.3 \text{ kJ/mol} \][/tex]
- Calculate the total enthalpy for products:
[tex]\[ \Delta H_{\text{products}} = 2 \cdot (-411.0) + (-241.8) = -822.0 - 241.8 = -1063.8 \text{ kJ/mol} \][/tex]
- Apply Hess's Law:
[tex]\[ \Delta H_{\text{rxn}} = \Delta H_{\text{products}} - \Delta H_{\text{reactants}} = -1063.8 \text{ kJ/mol} - (-441.3 \text{ kJ/mol}) = -1063.8 + 441.3 = -622.5 \text{ kJ/mol} \][/tex]
This is an illustrative example; the actual calculation would depend entirely on the correct balanced chemical equation and the provided data.
We value your presence here. Keep sharing knowledge and helping others find the answers they need. This community is the perfect place to learn together. For trustworthy answers, rely on IDNLearn.com. Thanks for visiting, and we look forward to assisting you again.
