labs

lab 1 aldehyde and ketone

Ex:- acetone also call carbonyl group test used to distinguish ald. and ketone Tollen,s test is used to identify the aldehyde . tollen,s reagent 1-(( silver nitrate AgNO3 )) 2-sodium hydroxide (( NaOH )) 3-ammonia NH3

silver nitrate sodium hydroxide

Black ppt. silveroxide

sodium nitrate

Silver ammonia complex Tollen ,s reagent


procedure In two clean test tube put 1- 10 drop of tollen reagent 2-then added to the first one 5 drops of acetaldehyde then added to the second one 5 drops of acetone wait 1 min , silver mirror deposited on the side the test tube in aldehyde (because aldehyde contain H atom ) and no reaction in the 2nd tube because ketone is not contain H atom Fehling test:Fehling solution consist of :- 1- fehling solution one : CuSO4 cupper sulfate-blue colour 2- fehling solution two : sodium –pottasium tartarate principle of fehling test aldehyde act as reducing agent it can reduce the deep blue colour of fehling solution in to red ppt. of cuprous oxide

Ald.

Cupric ion
Carboxyl ion
red ppt.. of cuprous oxide
acetone
Cupric ion



procedure in two clean test tube put 1- 5 drop of fehling 2- 15 drop of fehling mixed very well then added to the first one 10 drops acetaldehyde and to the second 3 drops acetone mixed very well , then put the tubes in a boiling water bath for 3-5 min, red ppt. appears in the first tube indicate the presence at aldehyde (because it contain H atom ) , In the 2nd no change in colour (remain blue colour ) because it contain ketone (absence of H atom )

Conclusion

Observation
test
Tollen,s test
Silver mirror
aldehyde acetaldehyde
No reaction
ketone acetone
Fehling test
Red ppt.
aldehyde acetaldehyde
blue colour (no reaction )
ketone acetone

lab 2 Analysis of group and test of the ions within the group

Soluble complex


filtrated ppt Ag+1 black ppt. to identify Ag indicate the added 1 drop of phenonaphthalene solution presence Hg2+2 then added (4M)HCl drop by drop until white ppt. appear indicate the presence for Ag+1

Test

Observation
Conclusion
Silver
White ppt.
Indicate the presence of Ag+ ion
Lead
Yellow ppt
Indicate the presence of Pb+2 ion
Mercurous
Black ppt
Indicate the presence of Hg2+2 ion

lab 3 Determination of PH

Determination of PhDetermination of pH = means determination the power of H+ in the solution pH define as = the negative Log of hydrogen ion conc. pH = - Log(H+) Table -1-pH of some fluid .1- blood plasma = 7.42-pancreatic juice = 83-gastric juice = 1.2 – 34-urine = 5 – 85-pepsine = 2 The fluid of all living organism contain conjugated acid or base which act as buffer In determination of pH we should know the following . 1- indicator .means an organic dyes which change their colour with change of the pH

pH of some indicators

pH
1
phenolphthalein
8.8-10
2
Methyl orange
2.9-4.6
3
Thymol blue. (acid)
1.2-2.8
4
Thymol blue. (base)
8-8.4
5
Phenol red
6.8-8.4
6
Bromophenol blue .
2.8-4.4
7
Bromothymol blue
6-7.6


1-universal indicator paper2-universal indicator solution method used for determination for determined pH value .1-by litmus paper . only for acid solution or basic solution .2-by universal indicator . ( paper solution )3-colorimetric method by ( Lovibond method ) .4-Electro metric method by ( pH – meter ) **By universal indicator paper and solution procedure ;1-clean 5 test tube put 10 drops solution 1,2,3,4,5 2-cut small piece of universal indicator paper then put one of solution to the end of the paper and allow to the dry for 1min ,then compare the color on the chart . record the result .3-add to each tube 1 drop of universal indicator mixed and compare colour with the colour on the chart then record the result .

No. of solution

pH univ. (paper colour )
pH univ. solution
1
2
3
4
5


** Electrometric method.Is the best method for determine pH . It depend upon the tension set between two electrode . positive and negative or depend upon the measurement of electrometric force between H+ and OH- in the solution . PH meter consist of :-1-the + ve electrode called (calomel electrode ) is made by .( Hg / HgCl and saturated solution of KCl ) It is called (reference electrode )2-the –ve electrode is glass electrode . which filled with 0.1 N HCl . when there two electrode . placed in the solution a different of potential . develops between the solution inside the electrode and that outside. The value depend upon the conc. of H+ outside the electode because the conc. of H+ inside the electrode remane constant

lab 4 Titrimetric analysis

Titrimetric analysis : Means to find the quantity of substance by using titration Titration : is the process of addition of standard solution of known concentration to another unknown substance until the reaction complete , this can be obtained by using indicator . Standard solution : The reagent exact known concentration used in titration Equivalent point (end point): the point at which amount of the standard solution equivalent to the substance that react during titration . Indicator :- Chemical compound that charge their colour with change the PH Primary standard solution :- High purified chemical compound and stable . Normality : Is the unit to measure the concentration . Of the solution .

No. of equivalent of solute N = ……(1) Volume of solution (liter) Or No. of miliequivalent of dissolved solute N = ..…(2) Volume of solution (liter) weight No. of equivalent = ……(3) Equivalent wt weight Ч 1000 No. of miliequivalent = …..(4) Equivalent wt Molecular wt Equivalent wt = No of charge wt wt Ч 1000 N = or N = equivalent Ч V (liter) equivalent Ч V (ml)


Procedure : fill the burette with HCl solution. Measure (5 ml) of unknown solution Na2CO3 . by pipette and put in conical flask. Add one drop of methyl orange indicator yellow colour appear Titrate HCl aqunist Na2CO3 by adding drop by drop till the pink colour appear stopped the titration and calculation .