Thermochemistry Vocabulary
The average kinetic energy of molecules.
What is temperature?
Name of the device used to measure heat changes.
What is a calorimeter?
In the heat energy equation, m stands for
What is mass?
Convert 1 calorie to joules.
4.18 J
A metal spoon is placed in a cup of hot tea. After a minute, the spoon feels warm. In what direction is heat moving?
Heat moves from the hot tea to the metal spoon.
A form of energy that always flows from warmer objects to cooler objects.
What is heat?
What simple household item can act as a basic calorimeter in class?
What is a styrofoam cup or soda can?
In the heat energy equation, ΔT stands for
What is change in temperature (Tf - Ti)?
How many Joules are in 2.5 kcal?
10,450 J
A rock that was sitting in the sun is placed into a cool bucket of water. In what direction is heat moving?
Heat flows from the hot rock to the cool water.
process that occurs when an object absorbs heat
What is endothermic?
This is why water takes longer to heat up than metal.
What is water has a higher specific heat than metal?
In the heat energy equation, c stands for
specific heat capacity
How much energy (in J) is needed to heat 500 g of water from 20°C to 80°C?
125,400 J
An ice cube is dropped into a bowl of hot soup.
Which object is gaining heat? What will happen to the temperature of each substance over time?
The ice cube gains heat.
The ice cube will increase in temperature and likely melt.
The hot soup will decrease in temperature.
Define the term "thermochemistry"
The study of heat changes that occur during chemical reactions and physical processes.
Is melting ice an endothermic or exothermic process?
What is endothermic?
In the heat energy equation, q stands for
What is heat energy?
A solar panel absorbs 1,000,000 J. How much water (g) could this heat from 25°C to 60°C?
6,834 g.
Three metal blocks—aluminum, copper, and iron—are placed outside in direct sunlight for the same amount of time and at the same angle. They each have the same mass and size.
The specific heats of the metals are:
aluminum: 0.90 J/g°C
copper: 0.39 J/g°C
iron: 0.45 J/g°C
After 30 minutes in the sun, which metal block will be the hottest?
copper
Define the term "exothermic"
What is process that occurs when a reaction or object loses/gives off/releases heat?
What happens to the water in a calorimeter when an exothermic reaction occurs?
What is the water temperature increases?
What is the specific heat of water INCLUDING UNITS?
4.18 J/goC or 1.00 cal/goC
How much heat is lost when 300 g of water cools from 80°C to 35°C?
56,430 J
Three unknown chemical samples—Substance A, Substance B, and Substance C—each start at a temperature of 25°C. They are placed in identical containers and left outside in direct sunlight for 30 minutes under the same conditions. Each sample has the same mass and absorbs the same amount of energy from the sun.
After 30 minutes, their temperatures are recorded:
Substance A: 52°C
Substance B: 67°C
Substance C: 44°C
Which substance has the highest specific heat capacity?
Substance C