1. All your burette readings(initial and finals) as well as the size of your pipette must be recorded but NO account of experimental procedure is required.
A is a Solution containing 1.04g HCl per 500cm3 of solution.
B is prepared by diluting 50.0cm3 of saturated solution of Na2CO3 at room temperature to 100cm3
(a.) Put A into the burette and titrate it against 20.cm3 or 25.0cm3 portions of B using Methyl Orange as an indicator.
Repeat the titration to obtain consistent titres.
B.) Tabulate your result and calculate the
(i) Concentration of A in mol/dm3
(ii) Concentration of B in Mol/dm3
(iii) Solubility of Na2CO3 in mol/dm3
(iv) Volume of CO2 that would be liberated from 1dm3 of B if the titration were carried out at S.T.P.
The Equation for the Reaction: Na2CO3 + 2HCl = 2NaCl + H2O + CO2.
TABLE OF VALUE:
Bur Rd|Rough|1st|2nd |3rd
Initial|0.00|0.00 |10.00 |0.00
NOTE: Rough,1st titre,2nd titre,3rd titre are all in (cm3)
AVERAGE VOLUME OF ACID USED
(Bi) Conc. of A in g/dm3
Molar mass of HCl
= 1*35.5 = 36.5g/dm3
.:. Conc. of A in mol/dm3
= 2.08/36.5 = 0.057mol/dm3.
(ii) CaVa/CbVb = Na/Nb
= 0.057*24.90/Cb*25 = 2/1
Cb = 0.057*24.90/25*2
(iii) To calculate the Solubility of Na2CO3 in Mol/dm3.
The dilution factor of B = 50 to 1000 mole of Na2CO3 liberate 22.4dm3 of CO2 at S.T.P.
(iv).:. 0.0284mole of Na2CO3 will liberate 22.4*0.0284
=0.64dm3 of CO2.
2. (a) TEST:
Put all of C in a boiling tube and cee about 5cm3 of distilled water. Divide the resulting solution into two portions.
White residue partially dissolved.
To the first portion, add about 2cm3 of BaCl2 solution.
*INFERENCE: SO4^2-,CO3^2-, SO3^2- Suspected.
The dilute HCl in excess
INFERENCE: Cl^- Present.
To the second portion of the solution, add two drops of phenolphthalein indicator.
Pink colouration observed.
Dissolve all of D in a boiling tube with about 5cm3 of distilled water. Divide the resulting solution into two equal parts.
Partially soluble in water.
*INFERENCE: Ca^2+, Pb^2+, Zn^2+ Suspected.
To the first portion, add ammonia solution.
White gelatineous ppt
To the second portion, add NaOH solution in Drop.
White ppt formed.
Then in excess.
Insoluble in excess.
(NOTE THAT THE ABOVE SOLUTION WILL BE IN A TABULAR FOR i.e
QUESTION NO 3. DO IT URSELF