Lab Quiz 1 Flashcards
What type of property is density?
Physical
What is accuracy?
How close the measurement is to the accepted value or theoretical value
What is precision?
The repeatability of measurement
How do you find deviation?
The average subtracted from individual measurements
What is a mixture?
Matter containing two or more substances
What is a heterogenous mixture?
All of the elements retain their individual identities
What is centrifugation?
The process of separating a solid or a precipitate from a liquid by whirling the mixture at a very high speed
What is decantation?
The process of separating a liquid from a precipitate or a solid by carefully pouring off the liquid and leaving behind the solid
What is distillation?
The process by which a liquid is brought to its boiling point, vaporized, then condensed and collected
What is extraction?
The process of separating one substance from another because it has a greater solubility in a different solvent
What is filtration?
The process of removing a solid or a precipitate from a liquid by using a porous barrier, membrane, paper filter, etc. to prevent the movement of of the solid or precipitate through the barrier
What is sublimation?
The process whereby a solid changes directly into a gas without a liquid phase being present
How do you find the percent error?
Theoretical minus experimental divided by theoretical times 100
How do you find the empirical formula?
Find the experimental number of moles of each element and divide by the smallest number of moles, multiply by until all are integers (if necessary)
What does “water of hydration” or “water of crystallization” mean?
When water is bonded to a structure of a substance
What are hydrates?
Substances with water bonded to them
What does anhydrous mean?
When a crystal solid does not contain water molecules bonded to its crystalline structure
What does effloresce mean?
The hydrates lose their water of hydration naturally when the water vapor pressure int he air surrounding them drops
What is a desiccant?
Salts that absorb moisture from the air to form hydrates (drying agents)
What is a dessicator?
A glass vessel with a tight closing lid used to keep samples dry
What does deliquescent mean?
Salts that absorb moisture from the atmosphere and create a hydrate or solution
What is a primary standard?
Any highly stable substance whose purity is extremely high
What is a titration?
The use of a burette to quantitatively deliver a known amount of a solution of known concentrate as it reacts with a known amount of a solution of unknown concentration
What is the end point or equivalence point?
When the two reactants are chemically equivalent
Usually when the color of an indicator is retained in a titration
