Enthalpy - MCAT Chemical and Physical Foundations of Biological Systems

1. 

2. 

3. 

We need to add the given processes in such a way that leaves on the left side, and on the right.

Since there are no in the final equation, begin by combining processes 1 and 2 to eliminate.

First, reverse process 2 and multiply by two:

2a)

2a)

2a)

Add this result to process 1.

1. 

2a)

1+2a)

Now we need to combine with process 3 to eliminate the . Start by multiplying process 3 by two.

3a)

3a)

Add this to the combined result from processes 1 and 2.

1+2a)

3a)

1+2a+3a)

This gives our final combination. The elemental reaction is , and the enthalpy of the process is .

Hess's law states that the enthalpies of the steps in an overall reaction can be added in order to find the overall enthalpy. Since the overall enthalpy of the reaction is +68kJ, we can use the following equation to find step 2's enthalpy.

1. 

2. 

3. 

We need to add the given processes in such a way that leaves on the left side, and on the right.

Since there are no in the final equation, begin by combining processes 1 and 2 to eliminate.

First, reverse process 2 and multiply by two:

2a)

2a)

2a)

Add this result to process 1.

1. 

2a)

1+2a)

Now we need to combine with process 3 to eliminate the . Start by multiplying process 3 by two.

3a)

3a)

Add this to the combined result from processes 1 and 2.

1+2a)

3a)

1+2a+3a)

This gives our final combination. The elemental reaction is , and the enthalpy of the process is .

Hess's law states that the enthalpies of the steps in an overall reaction can be added in order to find the overall enthalpy. Since the overall enthalpy of the reaction is +68kJ, we can use the following equation to find step 2's enthalpy.

1. 

2. 

3. 

We need to add the given processes in such a way that leaves on the left side, and on the right.

Since there are no in the final equation, begin by combining processes 1 and 2 to eliminate.

First, reverse process 2 and multiply by two:

2a)

2a)

2a)

Add this result to process 1.

1. 

2a)

1+2a)

Now we need to combine with process 3 to eliminate the . Start by multiplying process 3 by two.

3a)

3a)

Add this to the combined result from processes 1 and 2.

1+2a)

3a)

1+2a+3a)

This gives our final combination. The elemental reaction is , and the enthalpy of the process is .

Hess's law states that the enthalpies of the steps in an overall reaction can be added in order to find the overall enthalpy. Since the overall enthalpy of the reaction is +68kJ, we can use the following equation to find step 2's enthalpy.

1. 

2. 

3. 

We need to add the given processes in such a way that leaves on the left side, and on the right.

Since there are no in the final equation, begin by combining processes 1 and 2 to eliminate.

First, reverse process 2 and multiply by two:

2a)

2a)

2a)

Add this result to process 1.

1. 

2a)

1+2a)

Now we need to combine with process 3 to eliminate the . Start by multiplying process 3 by two.

3a)

3a)

Add this to the combined result from processes 1 and 2.

1+2a)

3a)

1+2a+3a)

This gives our final combination. The elemental reaction is , and the enthalpy of the process is .

Hess's law states that the enthalpies of the steps in an overall reaction can be added in order to find the overall enthalpy. Since the overall enthalpy of the reaction is +68kJ, we can use the following equation to find step 2's enthalpy.

1. 

2. 

3. 

We need to add the given processes in such a way that leaves on the left side, and on the right.

Since there are no in the final equation, begin by combining processes 1 and 2 to eliminate.

First, reverse process 2 and multiply by two:

2a)

2a)

2a)

Add this result to process 1.

1. 

2a)

1+2a)

Now we need to combine with process 3 to eliminate the . Start by multiplying process 3 by two.

3a)

3a)

Add this to the combined result from processes 1 and 2.

1+2a)

3a)

1+2a+3a)

This gives our final combination. The elemental reaction is , and the enthalpy of the process is .

Hess's law states that the enthalpies of the steps in an overall reaction can be added in order to find the overall enthalpy. Since the overall enthalpy of the reaction is +68kJ, we can use the following equation to find step 2's enthalpy.

1. 

2. 

3. 

We need to add the given processes in such a way that leaves on the left side, and on the right.

Since there are no in the final equation, begin by combining processes 1 and 2 to eliminate.

First, reverse process 2 and multiply by two:

2a)

2a)

2a)

Add this result to process 1.

1. 

2a)

1+2a)

Now we need to combine with process 3 to eliminate the . Start by multiplying process 3 by two.

3a)

3a)

Add this to the combined result from processes 1 and 2.

1+2a)

3a)

1+2a+3a)

This gives our final combination. The elemental reaction is , and the enthalpy of the process is .

Hess's law states that the enthalpies of the steps in an overall reaction can be added in order to find the overall enthalpy. Since the overall enthalpy of the reaction is +68kJ, we can use the following equation to find step 2's enthalpy.

1. 

2. 

3. 

We need to add the given processes in such a way that leaves on the left side, and on the right.

Since there are no in the final equation, begin by combining processes 1 and 2 to eliminate.

First, reverse process 2 and multiply by two:

2a)

2a)

2a)

Add this result to process 1.

1. 

2a)

1+2a)

Now we need to combine with process 3 to eliminate the . Start by multiplying process 3 by two.

3a)

3a)

Add this to the combined result from processes 1 and 2.

1+2a)

3a)

1+2a+3a)

This gives our final combination. The elemental reaction is , and the enthalpy of the process is .