Final Exam Terms Fall

Question 1

Uncertainty

Answer 1

used in a measurement to tell how well something is known…degree of potential error

Question 2

Scientific Uncertainty

Answer 2

A range of possible values in which the actual value lies

Question 3

What is the detection limit?

Answer 3

How to determine the uncertainty on different instruments

Question 4

Examples of detection limits

Answer 4

graduation lines, table provided, last decimal place

Question 5

Implicitly Reporting Uncertainty

Answer 5

Showing all values in the decimal place where the uncertainty lies

Question 6

Explicitly Reporting Uncertainty

Answer 6

Showing all values in he decimal place where the uncertainty lies and stating the uncertainty

Question 7

what is the max weight for a weighing vial?

Answer 7

120g

Question 8

what does uncertainty indicate?

Answer 8

reliability of the device

Question 9

Personal / Human Error

Answer 9

you made a mistake in the lab.

Question 10

Random Error

Answer 10

caused by an unknown and unpredictable changes in a measuring instrument or in the environment

Question 11

Percision

Answer 11

measure of the reproducibility of an experiment and quantifies random error

Question 12

how to determine percision?

Answer 12

1/2 range, and STDEV

Question 13

Systematic Error

Answer 13

occurs when there are flaws in the measuring device itself

Question 14

What causes systematic error?

Answer 14

incorrect calibration, design flaw, incorrect method for problem

Question 15

Accuracy

Answer 15

how close you come to the actual aimed for value

Question 16

how to determine accuracy?

Answer 16

% Error

Question 17

Mixture

Answer 17

when two or more substances that do not react chemically are united

Question 18

how to separate a mixture?

Answer 18

physical means

Question 19

Homogenous Mixture

Answer 19

also called solutions, appear uniform throughout

Question 20

Heterogenous Mixture

Answer 20

ar enot uniform throughout

Question 21

Physical Separation

Answer 21

using differences in physical properties of the compound of a mixture, such as solubility, boiling point, to separate.

Question 22

Examples of Physical Separation?

Answer 22

Extraction, Evaporation, Sublimation, Decantation, Filtration.

Question 23

Extraction

Answer 23

separation of a substance from a mixture by preferentially dissolving that substance in suitable solvent. By doing this, a soluble compound is usually separated from the insoluble compound.

Question 24

Evaporation

Answer 24

involves heating a solution to remove the solvent.

Question 25

What is left over in an evaporation?

Answer 25

residue. is the substance originally dissolved in the solvent

Question 26

Sublimation

Answer 26

process in which a solid passes directly to the gaseous state without going through the liquid state.

Question 27

Decantation

Answer 27

Separating a liquid from a solid "sediment" by gently pouring the liquid from the solid so as not to disturb the solid

Question 28

What is the liquid called in decantation?

Answer 28

Supernatant Liquid

Question 29

Filtration

Answer 29

separating solid from liquid by porous substance

Question 30

what is the liquid called in filtration?

Answer 30

filtrate

Question 31

Two types of filtration?

Answer 31

Gravity & Vacuum

Question 32

Chemical Separation

Answer 32

involves the selective reaction of one of the components of a mixture to form a new substance

Question 33

Chromatography

Answer 33

Process that permits the separation of a mixture into its components as a result of differences in rates in which the component travels through the column

Question 34

Mobile Phase

Answer 34

Gas, liquid

Question 35

Stationary Phase

Answer 35

film absorbed, paper, granular or porous solid

Question 36

Migration

Answer 36

based upon the repeated transfer of solute molecules back and forth between the two phases as solute is being swept down the column

Question 37

What technique did we use for gas chromatography?

Answer 37

Flame Ionization Detector (FID)

Question 38

Peak Area

Answer 38

directly proportionate to concentration

Question 38

Retention Time

Answer 38

time started to time it comes off. This is a characteristic of the specific component.

Question 39

Emperical Formula

Answer 39

shows the smallest whole number ratio in which the atoms combine to form a compound

Question 40

Molecular Formula

Answer 40

Gives the actual number of atoms in a molecule

Question 41

Law of Definite Proportions

Answer 41

The combining ratio of elements in a particular compound is constant regardless of the method of preparation

Question 42

Law of Multiple Proportions

Answer 42

When the same elements combine to form two different compounds, the two compounds will have different mass ratios.

Question 43

What is a dessicator?

Answer 43

a sealed container that keeps moisture out to protect and dry samples, chemicals, and other sensitive items:

Question 44

When to substances combine to form a compound

Answer 44

combination reactions

Question 45

When the compound breaks apart to form two or more products

Answer 45

decomposition

Question 46

when one element displace another element from a compound

Answer 46

single displacement

Question 47

Redox Reactions

Answer 47

when the oxidation states of one or more substances changes. Transfer of valence electrons.

Question 48

When do ion combination reactions form?

Answer 48

precipitate formation, gas formation, form a weak acid or non electrolyte

Question 49

Limiting Reagent

Answer 49

reagent that is used up first in a reaction

Question 50

Titration

Answer 50

a technique of accurately measuring the volume of a solution required to react with another reagent

Question 51

What does it mean for something to be standardized?

Answer 51

It went through the process of determining the exact concentration

Question 52

Auto-Catalytic Reaction

Answer 52

it produces its own catalyst

Question 53

what does a pale pink color mean in titration

Answer 53

reaction is complete.

Question 54

Enthalpy Change

Answer 54

the energy change of a reaction that occurs at standard conditions

Question 55

what values are enthalpy change for exothermic reactions?

Answer 55

less than zero

Question 56

what values are enthalpy change for endothermic reactions?

Answer 56

greater than zero

Question 57

calorimetery

Answer 57

the heat liberated during a reaction that causes a temperature change

Question 58

what is the calorimeter constant?

Answer 58

the heat absorbed from its surrondings, making it "imperfect"