21-23

Question 1

Qualitative Analysis

Answer 1

Identification of a specific substance present

Question 2

Quantitative analysis

Answer 2

The determination of the quantity of substance present

Question 3

Colorimetry

Answer 3

Analysis by color, light emitted, absorbed or transmitted by chemical used

Question 4

Gravimetric analysis

Answer 4

Uses stoichiometric calculations from the mass of a reagent

Question 5

Titration analysis

Answer 5

Uses stoichiometric calculations from the volume of a reagent

Question 6

Flame test

Answer 6

Some ions impart specific colours when subjected to flame, detect the presence of several metal ions

Question 7

Solution color

Answer 7

Some ions create specific colours when in solution, most aqueous solutions are colourless. Solutions containing monatomic and polyatomic ions of the transition elements have a visible colour (due to ions interference with light)
Ions absorb specific wavelengths of light, % of light that is absorbed depends on concentration of that ion

Question 8

Precipitates

Answer 8

Understanding the solubility table, we can determine what ions are in solution by whether or not a precipitate is formed

Question 9

Atomic absorption spectrophotometer

Answer 9

Used to analyze the light absorbed by a sample vaporized in a flame, can detect minute quantities of substances

Question 10

Precipitation reaction

Answer 10

Is a reaction where a slightly soluble product (precipitate) is formed

Question 11

Limiting reagent

Answer 11

Reactant whose entities are completely consumed in a reaction, reaction stops when all of this reactant is used up and none remains

Question 12

Excess reagent

Answer 12

Other reactant must be present in greater quantity, some will remain when limiting reagent has completely reacted

Question 13

Titration analysis

Answer 13

Used to determine the amount concentration of substances in solution, the process of carefully measuring and controlling the addition of a solution (titrant) from a burette into a measured volume of another solution(sample) in an Erlenmeyer flask until the reaction is judged to be complete

Question 14

Burette

Answer 14

Precisely marked glass cylinder with a stop cock at one end, it allows you to control and measure the volume of the reacting solution.
When doing a titration there will be a point when it is complete. Chemically equivalent amounts mole ratio will have been added

Question 15

Equivalence point

Answer 15

Point at which the exact theoretical amount of titrant has been added to completely react with the sample, look for sudden change in observable property (color, pH, conductivity)

Question 16

Endpoint

Answer 16

Point during a titration when this sudden change is observed, titration is stopped and the volume of titrant is determined

Question 17

Standard solution

Answer 17

A solution of a highly certain concentration

Question 18

Primary standard

Answer 18

A chemical that can be obtained at high purity with a mass that can be measured to High accuracy and precision, this is not possible with some chemicals

Question 19

Standardizing a solution

Answer 19

Means finding the concentration of the solution after it is prepared by reacting with another solution that has been prepared from a primary standard, stoichiometry is used to find unknown concentration

Question 20

Acid base reactions

Answer 20

Normally invisible in solution so it is difficult to tell just by looking when reaction is complete, use Indicators (will change color whether they are in an acid or a base) to give you an observable endpoint

Question 21

Interpreting titration pH curve

Answer 21

When creating pH curve the addition of titrant is not stopped at the endpoint, is continued until large excess has been added will be a very rapid change in pH passing equivalence point
**equivalence point is at the centre of change where curve is nearly VERTICAL

Question 22

Titration curve of acid and bases

Answer 22

Strong base reacting with acid, the pH abruptly changes from high to low
If titration is done in reverse pH starts low and ends high

Question 23

Net ionic equations for monoprotic bases

Answer 23

Strong monoprotic base reactions net ionic equation will always be: OH-(aq) + H+ (aq)&raquo_space; HOH (l)
Ions other than hydrogen/hydroxide are spectator ions

Question 24

Strong monoprotic» strong monoprotic base titration

Answer 24

Must have a pH of 7 at equivalence point
For every other acid-base reaction equivalence point solution will contain ions or molecules that are not spectators, pH will vary depending on which entities are present in what concentration

Question 25

Reading equivalence point

Answer 25

An equivalence point is read from a pH curve by estimating the inflection point position in the curve where it steepens.

Question 26

Inflection point

Answer 26

Is the point where the direction of the curvature changes like the centre point of the letter S

Question 27

If diprotic (reacts twice with hydrogen ions)

Answer 27

2 places where curve steepens, use the second equivalence point= we want pH value when reaction is complete

Question 28

Choosing acid base indicators

Answer 28

Must plot pH titration curve, endpoint observed must match equivalence point of the reaction. Pick an indicator that will change colour across a pH range that has a central value close to pH of sample