Endo vs. Exo
Specific Heat
Thermochemistry Key Terms
Hodgepodge
100
Based on the picture, where is the energy going?
(Entering/Leaving) the system
Leaving the System
100
Based on the chart below that lists the specific heat, which of the following object will experience the least temperature change?
Berylium
100
This is the heat content of a system at constant temperature and it is denoted as "ΔH "
Enthalpy
100
How does heat spontaneously move from one object to another?
Heat moves from a hotter object to a cooler object.
200
Based on the picture, where is the energy going?
(Entering/Leaving) the system
Entering the System
200
Rank the following objects from least to greatest regarding their temperature change when heated.
(Least Temperature Change --> Greatest Temperature Change)
beryllium < calcium <copper < gold
200
This is a measure of the number of possible ways that the energy of a system can be distributed due to the randomness/disorder of particles in a system.
entropy
200
Determine the number of moles of 6.08 grams of SiO2.
(Hint: You need to use the periodic table for this to get the molar mass)
0.10 moles
Molar Mass: 60.08 g/mol
300
Based on the thermochemical equation, what kind of reaction will this be?
exothermic
300
Calculate the heat required to melt 205 g of Ice.
Given that Water's ΔHvap: 2257 J/g
Water's ΔHfus: 333.6 J/g
Values can be negative depending on the phase change
Useful Equations
q = mΔvaporization
q = mΔfusion
Answer is 68,400 J
300
What are the two units of energy that we use for this unit?
Joules (SI Unit)
400
Based on the thermochemical equation, what kind of reaction will this be?
Endothermic
400
How much energy being absorbed in Joules is required to heat 50.0 grams of iron with a temperature change of 55°C? The specific heat of iron is 0.444 J/g°C.
Useful Equations
q = mcΔT
Answer is 1220 J
400
This is the heat content of a system at constant temperature and it is denoted as "ΔH "
Enthalpy
500
Please give one real life example of an exothermic and endothermic reaction
Answers might vary based on Teacher's discretion
500
How much energy is released when 25.0 grams of aluminum metal is cooled from 125°C to 35°C? The specific heat of aluminum is 0.900 J/g°C.
Useful Equations
q = mc(Tfinal - Tinitial)
Answer is -2030 J
500
When we talk about the perspective about the heat exchange that is happening in the universe, what two things that it consists of?
System and Surrounding
500
Calculate the Standard Heat of Formation (ΔH) for this reaction. Is this exothermic or endothermic?
SO3 (g) + H2O (g) --> H2SO4 (aq)
Given that the ΔH of:
H2SO4: -909.27 kJ
H2O: -241.8 kJ
SO3: -395.7 kJ
Answer: -271.77 kJ (Exothermic)
Work:
H2SO4 ---> H2O + SO3
(-909.27) - (-241.8 + -395.7) = -271.77 kJ