Module 4: Drivers of Reactions Flashcards
True or false, when bonds break between atoms, it involves energy changes
true
What is an endothermic reaction? Provide an example.
A reaction that absorbs energy. The reaction gains energy to its surroundings. eg. photosynthesis.
What is bond energy?
The amount of energy required to break one mole of a covalently bonded gas.
What is another word for heat energy?
enthalpy (△H)
What is an exothermic reaction? Provide an example.
A reaction that releases energy (energy exits). The reaction loses energy to its environment. eg. combustion & cellular respiration.
What is activation energy?
The energy required to break bonds in reactants, to start a chemical reaction.
What is enthalpy?
The stored chemical energy in bonds.
Can enthalpy be measured?
No, but we can measure the change in enthalpy. (The told enthalpy change (△H) is the heat of the reaction.
What is the difference between heat and temperature?
Heat: a measure of thermal energu contained in an object (joules)
Temp: how hot an object is (the kinetic energy of particles) (degrees C or K)
What is specific heat capacity?
The amount of heat energy required to raise the temperature of 1 gram of a substance by 1 K.
If △H (enthalpy) is negative, the reaction is….
exothermic
If △H (enthalpy) is positive, the reaction is…
endothermic
What is entropy?
The measure of the number of possible arrangements of components available within a system. The order or disorder of the system.
When entropy increases…
it becomes more disordered
