Phy Sci Test

Chemical Change

A process that results in the transformation of one substance into another.

Physical Change

A change that affects one or more physical properties of a substance without altering its chemical composition.

Chemical Property

A characteristic of a substance that can only be observed during a chemical reaction.

Physical Property

A characteristic of a substance that can be observed or measured without changing the substance's identity.

Pure Substance

A material made of only one type of particle.

Homogeneous Mixture

A mixture that has a uniform composition throughout.

Heterogeneous Mixture

A mixture in which the composition is not uniform throughout.

Density Formula

Density (D) is defined as mass (m) divided by volume (V): D = m/V.

Standard Temperature and Pressure (STP)

Conditions under which the volume of a gas is commonly measured: 0°C (273 K) and 1 atm (101.3 kPa).

Specific Heat Formula

The amount of heat required to change the temperature of a unit mass of a substance by one degree Celsius: Q = m * c * ΔT.

Endothermic Process

A process that absorbs heat from the surroundings.

Exothermic Process

A process that releases heat to the surroundings.

Kinetic Energy

The energy an object possesses due to its motion, related to temperature.

Hvap

stage 4

Hfus

stage 2

Temperature Conversion to Kelvin

To convert Celsius to Kelvin, add 273.

Units of Pressure

760 mmHg = 1 atm = 101.3 kpa

Calculating Total Heat

The sum of all heat changes during phase changes and temperature changes.

Heat Transfer Equation

Q = m * C * ΔT, where m is mass, C is specific heat, and ΔT is the change in temperature.

Q = m * C * ΔT

stage 1, 3, 5

Endothermic

absorbs heat Ex. Melting, vapor

Exothermic

release heat Ex. Freezing, condenation

Temp

the measure of average kinetic energy

CH2O

4.18 “g/”c

Cgas

2.02

Csolid

2.06

Hfus

334 J/g

Hvap

2260 J/g

Examples of Chemical Properties

Reactivity with acid, flammability, oxidation states, and pH

EX. Physical Property

Color, smell, freezing point, boiling point, and density

chemical change

rusting of iron, where iron reacts with oxygen to form iron oxide.

What is a physical change?

Melting, freezing, boiling, dissolving, and chopping.

what is the first picture?

Compound

2nd picture is

mixture

3rd picture is

element

4 is

mixture

5 is

element

what is the gas law equation

Solution

A homogeneous mixture composed of two or more substances, where one substance (the solute) is dissolved in another (the solvent), such as saltwater.

gas law is it Kelvin or Celsius

kelvin

specific Heat is it kelvin or Celsius

Celsius

compound

H2O

element

Cu

pure substance

Homogeneous

mixture

Homo and hetero