➕ Chemistry - Chemical v Physical Properties Flashcards
Define:
★Matter
Matter is anything that has mass and takes up space (made of atoms).
Define and give examples of:
★chemical properties
Chemical properties can be observed only when matter undergoes a change to become an entirely different kind of matter.
Ex: reactivity, flammability, ability to rust/corrode, toxicity, acidity
Define:
Reactivity
Reactivity is the rate a substance tends to undergo a chemical reaction.
Define and give at least 5 examples of:
★ physical properties
A physical property can be observed/measured without changing the identity of the substance.
Ex: color, odor, density, normal melting point, normal boiling point, conductivity, magnetism, malleability, solubility
Define and give the examples of:
a phase (or state of matter)
A phase is a physically distinct form of a substance. Also called “state of matter”.
Solid, liquid, and gas are the three phases of matter that most chemistry courses will test.
Give the equation for:
★density (ρ)
ρ = m/V
Where:
- Mass (m) - the amount of matter in an object, measured in grams (g, kg, etc.)
- Volume (V) - how much space an object or substance takes up
★What units are used to measure weight?
newtons or pounds
Be careful! Mass and weight are NOT the same thing. Mass is measured in grams, whereas weight is measured in newtons or pounds. You will have the same mass on Earth as do on Mars, but not the same weight. Weight = mass*gravity. Earth’s gravity = 9.8 N/kg
Define:
★ gas phase
molecules or inert atoms are widely spaced except with they happen to collide
Define:
★ liquid phase
molecules or inert atoms are constantly in contact with others
Name 3 characteristic of the solid phase of matter:
★ solid phase
- atoms are closely spaced and may vibrate in position
- atoms do not change relative locations,
- solids may be formed from molecules, or they may be extended structures with repeating subunits (ex: crystals)
★Which two variables can be used to actively change the phase of a substance?
Temperature can be added or removed. In general, an increase in temperature drives the phase change solid⇒liquid⇒gas.
Pressure (Volume) can be added or removed. In general, an increase in Pressure (or decrease in Volume) drives the phase change gas⇒liquid⇒solid.
Temperature and heat are two different variables measured using different units. Name the units used for temperature. Name the units used for heat.
Temperature is measured in degrees: Kelvin (K), Fahrenheit (°F), Celsius (°C), or Rankine (°R).
Heat is a form of energy often measured in joules (J) or calories (cal).
What name is associated with a phase change from
- solid (ice) to liquid (water)?
- liquid (water) to solid (ice)?
- solid⇒liquid is melting (fusion)
- liquid⇒solid is freezing (solidification)
What name is associated with a phase change from
- gas (water vapor) to liquid (water)?
- liquid (water) to gas (water vapor)?
- gas⇒liquid is condensation
- liquid⇒gas is vaporization (boiling)
What name is associated with a phase change from
- gas (water vapor) to solid (ice)?
- solid to gas?
- gas⇒solid is deposition
- solid⇒gas is sublimation
Define and state the use of a:
Phase Diagram
A phase diagram is a graph of the physical states (solid, liquid, gas) of a substance given a range of temperature and pressure
What phase is the substance in sections A, B, and C in the below diagram?
- A represents the Solid phase region.
- B represents the Liquid phase region.
- C represents the Gas phase region.
Why are the slopes zero for plateaus A and B?
Zero slope means no temperature change. This occurs at these times because any heat input is dedicated to breaking bonds between molecules, instead of increasing temperature.
