Physical and Chemical Change; intro to balancing chemical equations Flashcards
Define Physical Change.
A change which does not alter the chemical composition of a substance
Define Chemical Change.
A change that alters the chemical composition of a substance
What general rule can you follow to determine whether a change is physical or chemical?
Physical changes are generally easier to reverse, whereas chemical changes are very difficult or impossible to reverse.
What kind of change is temperature?
Physical
Equation for the relationship between Fahrenheit and Celsius
F = 1.8(C) + 32
Use Algebra to reverse the relationship between Fahrenheit and Celsius.
C = (F - 32)/1.8
List the four phases.
Solid, Liquid, Gas, Plasma.
List the processes of phase change.
Melting, vaporizing, condensing, freezing, sublimation.
Define Sublimation.
Phase change in which a substance goes from a solid to a gas, skipping the liquid phase completley.
Define the Kinetic Theory of Matter.
The molecules/atoms that make up a substance have space in between them, and they are inn constant, random motion. The hotter the substance, the faster the motion.
Give an important principle that differentiates the natures of volume and mass.
Volume doesn’t necessarily get larger when you add substances together. However, mass always gets larger.
Rule for balancing a chemical equation.
You can change the numbers on the left of a molecule/compound, but you can’t change the subscripts. (This is because of the Law of Definite Proportions!)
Define Single Displacement Reaction.
A reaction in which one element or ion in a compound is replaced by a different element or ion
Define Double Displacement Reaction.
A reaction in which two elements or ions in two different compounds switch places, each becoming part of the other compound
Define Combustion Reaction.
The process by which a chemical reacts with oxygen to form one or more products as well as heat and usually light
