Unit 4.01 - 4.03 Flashcards
What can we consider when physical state of matter is altered?
The change is considered to be physical change, but the chemical properties remains the same.
Solid –> Liquid
Melting
- IMF weakened; energy absorbed
Liquid –> Gas
Boiling
-IMF broken; energy absorbed
Gas -> Liquid
Condensing
-IMF formed; energy released
Solid –> Gas
Sublimation
- IMF broken; energy absorbed
Gas –> Solid
Reverse sublimation or deposition
- IMF formed; energy released
Liquid –> Solid
Freezing
- IMF formed; energy released
In order to weaken bonds, is energy absorbed or released?
absorbed
In order to strengthen bonds, is energy absorbed or released?
released
Water can have a lower boiling point when….
pressure decreases.
What stays the same when a matter skips a phase when transforming?
Example: Solid –> Gas
The amount of energy stays the same
What happens to the particles when a solid is heated?
The particles gain energy, move around more, and eventually gain enough energy to break away from their fixed positions, break intermolecular forces, and for a liquid
What does continued heating lead to?
Leads to the liquid particles gaining sufficient energy and forms into a gas.
Define chemical reactions
When the atoms of a substance are rearranged to form a new substance
What are “Driving Forces” and what are examples of it?
Driving Forces are observable changes that often accompany chemical reactions
- A precipitate forms
- A change of energy in the form of heat or light
- Observe a color change (sometimes; has to be a permanent change)
- See the formation of a gas
- Observe electrical current (a flow of electrons)
How can you tell the difference between a chemical and physical change?
- If a new product forms, it’s a chemical change
- If chemical bonds are broken or made, it’s a chemical change
- If intermolecular forces are broken or made, it’s a physical change
Evaporation is a ________ process
cooling
Boiling is a _________
process
Explain the magnificent seven
The magnificent seven are diatomic elements that always appear in groups of 2 when they are alone.
Example: H2, N2, O2, F2, Cl2, Br2, I2
What must you do when balancing equations?
Only place numbers in front of the whole formula. Do not the change the “correct) formula of any of the reactants or products, or add extra formulas.
Define aqueous
Meaning in solution with water as the solvent
What are often carried out in aqueous solutions?
Many qualitative (quality; described in words) and quantitative (numbers) chemical reactions
What are electrolytes?
Ions in water
Define strong electrolytes
A large number of ions are present in a solution
- Breaks away completely
