Quantitative Relationship involving ⌂H and Hess's Law
For each generic reaction, determine the value of ⌂H2 in terms of ⌂H1
1) A + B → 2C ⌂H1
2C→A + B ⌂H2=?
2) A + 1/2 B → C ⌂H1
2A + B → C ⌂H2=?
3) A → B + 2C ⌂H1
1/2B + C → 1/2A ⌂H2=?
The answers are: 1) -⌂H1 2) 2⌂H1 3) -1/2⌂H1
What do you do?
For each generic reaction, determine the value of ⌂H2 in terms of ⌂H1
1) A + B → 2C ⌂H1
2C→A + B ⌂H2=?
2) A + 1/2 B → C ⌂H1
2A + B → C ⌂H2=?
3) A → B + 2C ⌂H1
1/2B + C → 1/2A ⌂H2=?
The answers are: 1) -⌂H1 2) 2⌂H1 3) -1/2⌂H1
What do you do?
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1. The first statement is an endothermic reaction. Because the second statement is the same elements & same quantities, but decomposing instead of synthesizing, it's the same amount of heat, but it's an exothermic reaction.
2. The quantities of both elements are doubled in the second statement, meaning the heat gets doubled as well.
3. The quantities are divided by 2, and like the second statement of number 1, the statement is flipped.
2. The quantities of both elements are doubled in the second statement, meaning the heat gets doubled as well.
3. The quantities are divided by 2, and like the second statement of number 1, the statement is flipped.