Question

question 6 of 10
points possible: 1.00
determine whether each described process is endothermic or exothermic.
a process with a calculated negative ( q ) choose...
wood burns in a fireplace choose...
ice melts into liquid water choose...
a process with a calculated positive ( q ) choose...
solid dissolves into solution, making an ice pack feel cold choose...
acid and base are mixed, making test tube feel hot choose...

Explanation:

• For a process with a calculated negative \( q \): In thermochemistry, \( q\) represents heat. A negative \( q\) means heat is released by the system (the process) to the surroundings. So, it is exothermic.
• For wood burning in a fireplace: Combustion reactions (like wood burning) release heat (and light). Heat is given off by the wood (system) to the room (surroundings), so it is exothermic.
• For ice melting into liquid water: Melting (fusion) requires heat input. The ice (system) absorbs heat from the surroundings (e.g., the air in the room) to break the intermolecular forces in the solid - ice structure and become liquid water. So, it is endothermic.
• For a process with a calculated positive \( q \): A positive \( q\) means heat is absorbed by the system from the surroundings. So, it is endothermic.
• For solid dissolving into solution, making an ice - pack feel cold: When the solid dissolves, the system (the dissolving solid) absorbs heat from the surroundings (the ice - pack, which we feel as cold). So, it is endothermic.
• For acid and base are mixed, making test tube feel hot: Neutralization reactions (acid - base reactions) release heat. The reaction mixture (system) releases heat to the test tube (surroundings), which we feel as hot. So, it is exothermic.

Answer:

1. Exothermic
2. Exothermic
3. Endothermic
4. Endothermic
5. Endothermic
6. Exothermic