Multiple Choice
Which of the following best describes the enthalpy change (ΔH) associated with an endothermic reaction?
62
views
8. Thermochemistry
Endothermic & Exothermic Reactions
Multiple Choice
Jan is holding an ice cube. What causes the ice to melt?
A
The ice absorbs cold from Jan's hand, causing it to melt.
B
Jan's hand provides pressure that causes the ice to melt.
C
The ice releases heat to Jan's hand, causing it to melt.
D
Heat flows from Jan's hand into the ice, increasing the ice's temperature until it melts.
Verified step by step guidance1
Understand that melting is a phase change where a solid (ice) turns into a liquid (water) by absorbing energy in the form of heat.
Recognize that heat always flows from a warmer object to a cooler one, so Jan's hand (warmer) transfers heat to the ice (colder).
Know that the ice does not absorb 'cold'; instead, it absorbs heat energy, which increases the ice's internal energy and temperature.
Realize that pressure from Jan's hand is not the primary cause of melting in this scenario; the key factor is the transfer of heat.
Summarize that the ice melts because heat flows from Jan's hand into the ice, raising its temperature to the melting point and providing the energy needed to break the bonds holding the ice molecules in a solid structure.
Related Videos
Related Practice
