Heat

energy

It is impossible to know the total content of a substance

Thermochemistry

Which is the term for the study of heat changes that accompany chemical reactions and phase changes?

Calorimeter

Which is the term for an insulated device used for measuring the amount of heat absorbed or released during a chemical or physical process?

1. Water absorbs the energy released in the reaction, or releases the energy absorbed by the reaction. 2. The data to be collected is the change in temperature of the water. 3. It is important that the mass of water used be known.

Which statements about how a calorimeter is used to measure energy that is absorbed or released are true?

The metal is heated and placed in the water in the calorimeter. The temperature change of the water is recorded.

Which statements best summarize how a foam-cup calorimeter can be used to determine the specific heat of an unknown metal?

1. A known mass of water is placed in an insulated chamber. 2. The initial temperature of the water recorded. 3. The reaction takes place and either releases energy to the water or absorbs energy from the water. 4. The water cools down or heats up accordingly. 5. The final temperature of the water is recorded.

Place these steps in order so that they describe how a calorimeter is used to measure energy that is absorbed or released.

1. Put a known mass of water into the foam-cup calorimeter. 2. Determine the initial temperature of the water. 3. Take a sample of metal or known mass and heat it up. 4. Place the metal into the water. 5. Once the temperature of the water stabilizes, record the temperature. 6. Use the temperature change data to calculate specific heat.

These steps describe how to determine the specific heat of an unknown metal using a foam-cup calorimeter. Put them in order from the first step to last step.

always have a positive sign

For endothermic reactions, the enthalpy changes

Exothermic

Heat flows from the system to the surroundings when a(n) reaction takes place

Enthalpy

The heat content of a system at constant pressure is its

surroundings to the system

During an endothermic reaction, heat flows from the

system

In thermochemistry, the specific part of the universe that contains the reaction or process you wish to study is the

Universe

In thermochemistry, the system plus the surroundings is the

The surroundings

In thermochemistry, which is everything in the universe other than the system?

products reactants

The enthalpy of reaction is equal to the enthalpy of the___ minus the enthalpy of the

exothermic

The sign of enthalpy changes for reactions is always negative.

0.235

The water in a calorimeter absorbed 355.3 J of heat when an unknown metal with a mass of 8.40 g cooled by 180.0°C. The specific heat of the metal was

134.7J / (2.50g)(120.0°C) = 0.449 J/(g⋅°C)

Using a calorimeter, it was determined that a piece of metal with a mass of 2.50 g absorbed 134.7 J of heat when its temperature increased by 120.0°C. What is the specific heat of the metal?

ΔHrxn = Hproducts - Hreactants

Which equation correctly shows how the enthalpy of reaction is related to the enthalpy of the reactants and products?

enthalpy of reaction

Which is the term for the change in enthalpy for a reaction?