by sign convention Δ
is negative it means an exothermic reaction where the heat is lose so the temperature decreases.
Answer:
The evidence showing that there is a chemical reaction taking place is the instantaneous temperature drop once the cold pack is shaken.
Explanation:
When an athlete applies a cold pack to the injury, they shake it before, mixing the water and <em>ammonium-nitrate fertilizer</em> inside the cold pack. This mixing is an endothermic reaction, which means it absorbs heat. In turn, the temperature falls to 35 F for around 10 minutes.
Answer:
12.78 kJ
Explanation:
The correct balanced reaction would be
Mass of methanol = 
Moles of methanol can be obtained by dividing the mass of methanol with its molar mass 
Enthalpy change for the number of moles is given by
The change in enthalpy is 12.78 kJ.
Those are the correct steps, young chemist. Don't be discouraged by an insane answer.
Answer:
Conversion of kinetic energy to potential energy (chemo mechanical energy)
In the state of rest, the rubber is a tangled mass of long chained cross-linked polymer that due to their disorderliness are in a state of increased entropy. By pulling on the polymer, the applied kinetic energy stretches the polymer into straight chains, giving them order and reducing their entropy. The stretched rubber then has energy stored in the form of chemo mechanical energy which is a form of potential energy
Conversion of the stored potential energy in the stretched to kinetic energy
By remaining in a stretched condition, the rubber is in a state of high potential energy, when the force holding the rubber in place is removed, due to the laws of thermodynamics, the polymers in the rubber curls back to their state of "random" tangled mass releasing the stored potential energy in the process and doing work such as moving items placed in the rubber's path of motion such as an object that has weight, w then takes up the kinetic energy 1/2×m×v² which can can result in the flight of the object.
Explanation:
