Exp 11 Flashcards
What is the difference between quantitative and qualitative?
Quantitative data is the data that can be measured and is determines how much of the chemical we have
Qualitative data is the data that can be seen and determine which chemical substance is present.
Give examples for qualitative and quantitative data
Qualitative : color smell precepetaion
Quantitative: volume, mass, density , length ,area and height
Is the volumetric method is it qualitative or quantitative?
Quantitative ( volume)
For example acid base titration
What is titration methods used for?
What type of reactions can we use the titration methods in ?
To know the concentration of an unknown substance in a solution
Acid-base titration and redox reaction
What is titration methods used for?
What type of reactions can we use the titration methods in ?
To know the concentration of an unknown substance
Acid-base titration and redox reaction
What is the end point in an acid base reaction?
The point where the amount of hydrogen cation in a solution is equivalent to the amount of hydroxide anion in the solution
What is an indecator ?
What dose it do?
And in which medium do we see the change?
Is the change caused by the indicator qualitative or quantitative ?
It is a substance that make the end point of a reaction visibility to make it easier to measure the concentration of the unknown .
It changes the solutions color to pink.
The change in color is qualitative .
Basic medium.
The lighter the pink ( color ) the closer it is from the end point .
What is the indicator used in this reaction?
Phenolphethalein
In this reaction which chemicals are used? 9 acid-base titration )
KHP as the acid( standard solution [known concentration ])
NaOH as the base (unknown concentration )
What types of standard solutions do we have?
Two :
Primary and secondary
What are the things that must be in a primary solution ?
What determine if the standard solution is primary or not ?
There are three things that must be in a subcutaneous to be considered as primary solution :
1- high purity
2- stable during storage ( isn’t effected by anything)
3- high molar mass
4- it could be standardized directly with only one reaction
NaOH , KHP
Which is primary
Which is secondary
KHP primary
NaOH secondary ( because it absorb the moist from the air )
What does back titration mean? And which chemical uses back titration?
Back titration is the indirect methods of titration [ uses multiple reactions ]
The secondary standard solutions. In this case it is NaOH
What is the mane of the property of NaOH ( absorbing the logistics of the air)
Hygroscopic
What are protocols acids?
It is the acid that are able to give hydrogen cation.
