Reagents And Titration Flashcards
Substance that is consumed during the course of the chemical reactionp
Reactant
A substance or compound that is added to a system in order to bring about a chemical reaction or see if a chemical reaction occurs
Reagent
A solution of hydrogen peroxide and an iron catalyst
Fenton’s reagent
Uses of fenton’s reagent
- oxidizing contaminants or waste waters
* destroy organic compounds such as trichloroethylene (TCE) and tetrachloroethylene (PCE)
Used to differentiate between water-soluble carbohydrate and ketone functional groups
Fehling’s solutiono
Uses of fehling’s solution
- differentiate water-soluble carbohydrate from ketone functional groups
- test for monosaccharides
Color of final fehling’s solution
Deep blue
Two solutions of fehling’s solution:
- fehling’s a : blue aqueous solution of copper (ii) sulfate
* fehling’s b : colorless aqueous solution of potassium sodium tartrate (rochelle salt) and a strong alkali
Analytical reagent used to detect the presence of soluble proteins
Millon’s reagent
Positive result of presence of tyrosine (millon’s reagent)
Reddish-brown
A chemical reagent used to determine the presence of an aldhyde or alpha-hydroxy ketone functional groups
Tollen’s reagent
Composition of tollen’s reagent
- silver nitrate
* ammonia
Positive test of tollen’s reagent
Precipitation of elemental silver forming a silver mirror
Used to detect ammonia or primary and secondary amines
Ninhydrin
Positive test of ninhydrin
Deep blue or purple color - Ruhemann’s purple
Uses of ninhydrin
- detect fingerprints - terminal amines
* detect ammonia or primary and secondary amines
Used for detecting the presence of peptide bonds
Biuret reagent
Positive test in biuret reagent
Copper (ii) ions form a violet- colored coordination complexes in an alkaline solution
Chemical test that distinguishes aldose between ketose sugars
Seliwanoff’s test
Positive test in seliwanoff’s test
- deep cherry red - dehydrated ketose
* faint pink - aldose
Used to detect the presence of reducing sugars
Benedict’s reagent
Positive test for benedicts reagent
Color change of clear blue to brick red
Uses of benedicts reagent:
- detect presence of reducing sugars
* includes monosaccharides and many disaccharides including lactose and maltose
Common lab method of quantitative chemical analysis that is used to determine the unknown concentration of an identified analyte
Titration
Other names of titration
- Volumetric analysis
* titrimetry
Play a key role in titration
Volumetric measurements
Reagent prepared as a standard solution
Titrant
Other name for titrant
Titrator
Other name of analyte
Titrand
Volume of titrant reacted
Titre
Titration set up
Beaker or erlenmeyer flask
Burette
Equal volume of acid and base
Equivalence point
Used in acid-base titrations
Phenolphthalein
In acidic solutions, phenolphthalein is
Colorless
In basic solution, phenolphthalein is
Pink
Ph indicator for weak acids and bases
Bromothymol blue
bromothymol blue turns _______ in acidic solution
Green to yellow
Bromthymolblue turns _______ in basic solution
Blue
Frequently used in titrations because of its clear and distinct color change
Methyl orange
Color change of methyl orange when solution becomes less acidic
Red-orange-yellow
In an acid, methyl orange is
Red
In a base, methyl orange is
Yellow
Used to calculate an unknown concentration of acid (or alkali) using a neutralization reaction
Titration experiment
Number of moles =
Concentration of base x volume of base
Concentration =
Number of moles / volume of acid
Titration is a common lab method of quantitative chemical analysis used to determine the unknown concentration of an identified ________
Analyte
A known concentration and volume of titrant reacts with a solution of ________ to determine concentration
Analyte or titrand
Small volumes of the titrant are then added to the _______ and _______ until the ________ changes color in reaction to the ___________________ reflecting arrival at the endpoint of the titration
- analyte and indicator
- indicator
- titrant saturation threshold
- endpoint
Upon reaching an endpoint the volume of _______ consumed is measured and used to _______ the concentration of analyte
- reactant
* calculate