Module 2: ACID-BASE TITRIMETRY: DIRECT TITRATION (PART 2)

Question 1

Materials, Glassware and Apparatus
- Used to “measure an exact LARGE volume” of liquid

Answer 1

Volumetric Flask

Question 2

Materials, Glassware and Apparatus
– There is a “small line” on the neck that indicates “how far to fill” the bottle

Answer 2

Volumetric Flask

Question 2

Materials, Glassware and Apparatus
– Use “CORK” as stopper if necessary, NOT your thumb!

Answer 2

Volumetric Flask

Question 3

Materials, Glassware and Apparatus
– A glass tube that is open at the top and comes to a narrow pointed opening at the bottom.

Answer 3

Burette

Question 4

Materials, Glassware and Apparatus
– Right above the bottom opening is a stopcock that can be turned to control the amount of liquid being released.

Answer 4

Burette

Question 5

Materials, Glassware and Apparatus
– There are “markings” along the length of the tube that indicate the volume of liquid present.

Answer 5

Burette

Question 6

Materials, Glassware and Apparatus
– Used for extremely accurate addition of liquid, especially during “TITRATION”

Answer 6

Burette

Question 7

Use “—-“ as stopper if necessary, NOT your thumb

Answer 7

CORK

Question 8

“Analytical method”
of determining the quantity of a reagent of known concentration (STANDARD SOLUTION) that is required to react completely with the amount of active constituent is sample being analyzed (analyte).

Answer 8

TITRIMETRY (Titrimetric Analysis)

Question 9

reagent of known concentration

Answer 9

STANDARD SOLUTION

Question 10

active constituent is sample being analyzed

Answer 10

analyte

Question 10

solution added from the burette

Answer 10

Titrant

Question 11

A “process” in which a standard reagent is added to a solution of analyte until the reaction is judged to be complete.

Answer 11

TITRATION

Question 11

Concentration and Volume

Answer 11

STANDARD SOLUTION

Question 12

mass

Answer 12

ANALYTE

Question 12

Determining the amount of standard solution to react with analyte

Answer 12

TITRIMETRY (Titrimetric Analysis)

Question 12

substance being titrated

Answer 12

Titrand

Question 13

During ASSAY…

The standard solution is considered as the ___________; while the analyte/sample as the __________

Answer 13

1. Titrant
2. Titrand

Question 13

Unknown concentration

Answer 13

analyte/sample

Question 13

standard solution is considered as the

Answer 13

Titrant

Question 13

Normality (N) Formula

Answer 13

𝑵 =

𝑬𝒒 𝒎𝑬𝒒
—- 𝒐𝒓 ——-
𝑳 𝒎𝑳

Question 13

A process to complete a reaction

Answer 13

TITRATION

Answer 14

Chemical Equivalence

Question 14

‘D’i alam ang concentration (analyte/sample) and nasa erlenmeyer flask

Answer 14

Titrand

Question 14

Standard Solution at the Burette

Answer 14

Titrant

Question 15

Milliequivalent Weight (mEq wt) Formula

! sample/analyte ay laging sinosolve-an ng mEq wt

Answer 15

𝒎𝑬𝒒 𝒘𝒕 =

   𝑴𝑾 ----------------- 𝒇𝒆𝒒 𝒙 𝟏𝟎𝟎𝟎

Question 15

Update the label of the prepared and standardized solution (now a standard solution) with the calculated AVERAGE normality.

– In this case, it’s 0.09627 N H2SO4.
– This value will be used in the following experiments.

Answer 15

Important note

Question 15

analyte/sample as the

Answer 15

Titrand

Question 15

𝑬𝒒𝒖𝒊𝒗𝒂𝒍𝒆𝒏𝒄𝒆 𝑭𝒂𝒄𝒕𝒐𝒓 formula

Note! – For neutralization reactions, feq represents the number of reacting H+ or OH- ions.

Answer 15

𝑬𝒒𝒖𝒊𝒗𝒂𝒍𝒆𝒏𝒄𝒆 𝑭𝒂𝒄𝒕𝒐𝒓 = 𝒇𝒆𝒒

= Acids - # of H
= Bases - # of OH
= Inorganic Salt - subscript of cation

Question 15

Normality (from average normality) formula

Answer 15

𝑵 =

       𝒈 -------------------- 𝒎𝑬𝒒 𝒘𝒕 𝒙 𝒎𝑳

Question 15

– It is defined as the number of equivalents of solute per liter of solution.
– Or milliequivalents per milliliter (mEq/mL)

Answer 15

Normality (N)

Question 16

In Standardization
the “concentration” of a solution is determined by titrating it against a __________.

Answer 16

primary standard

Question 16

The ______ is the standard working solution while the ______ is the primary standard

Answer 16

1. titrant
2. titrand

Question 17

the standard working solution is the

Answer 17

titrant

Question 18

the primary standard is the

Answer 18

titrand

Question 19

Normality of the solution can be calculated using the equation __________

Answer 19

𝑵 =
𝒈
——————–
𝒎𝑬𝒒 𝒘𝒕 𝒙 𝒎𝑳