Ch. 34 - The First Law of Thermodynamics

What two laws does every chemical reaction obey?

The Law of Conservation of Mass

The Law of Conservation of Energy

What is the First Law of Thermodynamics?

Energy can be converted from one form to another but cannot be created or destroyed

What is energy?

The capacity to do work

What are the main types of energy?

Radiant, Thermal, Chemical, Potential, and Kinetic

What is radiant energy?

The energy of electromagnetic wavesW

What is thermal energy?

Energy associated with the random motion of atoms and molecules

What is chemical energy?

Energy stored within the bonds of chemical compounds/substances

What is potential energy?

Energy that is available because of the object’s position

What is kinetic energy?

Energy that is produced by a moving object

What is thermochemistry?

The study of the heat change in a chemical reaction

What is thermodynamics?

The study of the relationships between heat and other forms of energy within a system

How can heat be transferred?

It can flow, be absorbed, or released

What does temperature measure: heat or thermal energy?

Thermal energy

Are heat and thermal energy the same thing?

No

What is calorimetry?

The process of measuring the amount of heat released or absorbed during a chemical reaction

What is the specific heat?

The amount of heat required to raise the temperature of 1g of a substance by 1°C

How much is 1 calorie in joules?

4.184J

Why is enthalpy useful?

It can tell you if the reaction will be endothermic or exothermic

What is the symbol for enthalpy?

The letter H

What is Hess’ Law?

It states that when reactants are converted into products, the change in enthalpy is the same regardless of how many steps it takes to get to the end product

What is an example of Hess’ Law?

If you go up 4 small steps vs one big step of equal height, you will still expend the same amount fo energy