(a) Place all solid R provide into a clean boiling tube then add about 5 cm³ of distilled water. Shake the contents thoroughly then filter. Retain both the filtrate and residue.

(b) Divide the filtrate into four equal portion. To the first portion, add sodium hydroxide solution until in excess.

(c) To the second portion, add about 2cm³ of Barium Chloride Solutions.

(d)  To the third portion, add 2 or 3 drops of lead II nitrate solution provided followed by about 2cm³ of 2M nitric acid then shake the mixture.

(e) To the fourth portion, add about1cm³ of dilute sulphuric (vi) acid.

(f) (i) Transfer all the residue into a clean boiling tube, then add about 2 cm3 of 2M nitric acid add about 5 cm³ of distilled water when all the solid has dissolved.

(ii) Divide the resultant product obtained in f (i) above into three equal portions. Add sodium hydroxide solution drop wise until in excess.

 (iii) To the second portion, add ammonia solution drop wise until in excess.

 (iv) To the third portion, add a few drops of potassium iodide solution.

You are provided with;

• Solution A; (xM hydrochloric acid)
• Solution B; (1M Sodium hydroxide solution)

You are required to:

- Determine the concentration of the HC1 in moles/litre.

- Determine the molar heat of neutralization of the hydrochloric acid.

Procedure:

1. Using a clean measuring cylinder measure 50.0cm³ of solution B into a plastic cup/beaker provided.

2. Measure and record in the table below the temperature of solution B.

3. Fill the burette with solution A.

Note:   You are required to add solution A into solution B in portion of exactly 5.0cm³ each.

4. Add the first 5.0cm³ portion of solution A to solution B in the beaker. Stir the mixture with a thermometer and record the highest temperature attained.

5. Add the other 5.0cm³ portion of solution B, stirring the mixture and record the highest temperature attained after each addition. Continue until a total volume of 50cm³ has been added.             

Questions

(a) Plot a graph of temperature against the volume of  a solution A added.             (3mks)

(b) From the graph, determine the volume of solution A that reacted completely with the 50 cm³ of solution B (lmk)

(c) Calculate the concentration of solution A in moles/litre.                                     (2mks)

(d) From the graph determine the maximum temperature rice when solution B is fully neutralized.                       (1mk)

(e) Calculate the molar heat of neutralization of solution A (hydrochloric acid).             (4mks)

Part  I

You are provided with Solid M carry out the tests below. Write your observations and inferences in the spaces         provided.

Place all the solid M in a boiling tube. Add about 10cm3 of distilled water. Shake until all the solid dissolves. Divide the solutions into five portions.

(i)To the first portion add 2M sodium hydroxide drop wise till in excess.

(ii) To the second portion add ammonia solution drop wise until in excess.

(iii) To the third portion add four drops of hydrochloric acid.

(iv) To the forth portion add 3 drops of lead (ii) Nitrate solution

(v) Warm the mixture obtained in (d) above.

                                                   Part II

You are provided with solid W. Carry out the tests. Write your observations and inferences in the spaces          provided.

Place ¾ of the solid W provided in a boiling tube. Add about 10cm3 of distilled water and shake until all the solid dissolves. Divide the solution into portion.

(i) To portion one add 3 drops of solution R

(ii) To the   portion two, add 5 drops of acidified potassium dichromate (vi)

(iii) To portion 3, add all the sodium hydrogen carbonate

(iv) To portion 4 add 3 drops of universal indicator and determine the pH

(v) Scoop the remaining Solid W using a metallic spatula. Ignite it in a bunsen burner flame.

You are provided with:

-2.3g of solid N in a boiling tube.

-Solution, 0.03M acidified potassium manganate (VII).

You are required to determine the number of moles of water of Crystallization in solid N.

Procedure (III)

(a) Add 10cm³ of distilled water into the boiling tube containing solid N shake it to dissolve the solid. Transfer the contents of the boiling tube into a 250cm³ volumetric flask. Rinse the boiling tube with the distilled water and add it to the volumetric flask. Add more distilled water to make it to the mark label this solution N.

Fill the burette with solution R. using a pipette and a pipette filler place. 25.0cm³ of solution N into a conical flask. Warm the mixture to about 60⁰C. Titrate the hot solution N with solution R until a permanent pink colour persists. Record your readings in table below . Repeat the titration two more times and complete table.                     

b) Calculate the :

i) Average volume of solution R used                                               (1mk)

ii) Number of moles of potassium manganate (VII) that reacted       (1mk)

iii) Number of moles of N in 25cm³ of solution N, given  that 5 moles of N reacts completely with 2 moles of potassium manganate (VII)  Solution R                                                (1mk)

iv)  Relative formula mass of N                                                  (1mk)

b) The formula of N has the form P. X H₂O. Determine the value of x in the formula  given that the relative formula mass of P is 90.0 and atomic masses of hydrogen and oxygen are 1.0 and 16.0 respectively.                                                 (2mks)

You are provided with sodium hydroxide solution L  1.8g of solid T, Solid T is a dibasic acid 0.36M Solution of the dibasic acid H₂X labelled solution Q.

            You are required to determine:

i) The molar heat of solution of solid T

ii) The heat of reaction of one mole of dibasic acid with sodium hydroxide.

Calculate the heat of reaction of solid H₂X with aqueous sodium hydroxide.

            Procedure I

Place 40cm³ of distilled water into a 100cm³ beaker. Measure the initial temperature of the water and record it in table I below. Add all the Solid T at once. Stir the mixture carefully with the thermometer until all the solid dissolves. Measure the final temperature reached, record it in table I and complete table I.                                                          (2mks)

                                        Table I

(b) Calculate the;

(i) Heat change when H₂X dissolve in water (Assume the specific heat capacity of the solution is 4.2J g ^{-1 0}C ^-1 and density is 1g / cm³ )                                                (2mks)

(ii) The number of moles of the acid that dissolved.  (Relative formula mass of H₂X is 126)     (1mk)

iii) Molar heat of solution,  H1, solution of the acid H₂X                                (1mk)

Procedure II

Place 40cm³ of solution Q into a 100cm³ beaker. Measure the initial temperature and record it in table II below. Measure 40cm³ of sodium hygroxide, solution L. Add all the 40cm³ of solution L at once to solution Q in the beaker. Stir the mixture with the thermometer. Measure the final temperature reached, record it in table II and complete the table         

                                        Table II

(b) (i) Calculate the heat change for the reaction (Assume the specific heat capacity of the solution is 4.2Jg ^{-1 0}C^-1  density  is  1g / cm³)                                    (2mks)

      (ii) Calculate the number of moles of H₂X used                       (1mk)

    (iii) Calculate the heat of reaction H of one mole of the acid H₂X with sodium hydroxide      (1mk)

(c) Given that :                                                                     (2mks)

            ∆H1 is the heat for the reaction. H2X (s)    ------------->           H2X (aq)

            ∆H2 is the heat for reaction H2X (aq)  + 2NaOH (aq) -----------> Na2X (aq)    + 2H2O (l)

Calculate   ∆H3 for the reaction H2X (s)  + 2NaOH (aq)  --------->  2H2O (l)  + Na2X (aq)     

You are provided with solid F.  You are required to carry out the test below.

(a)       Divide solid F into two equal parts.  To the first portion, ignite using a metallic spatula

and a blue Bunsen burner flame

(b)       Place the remaining portion of solid F in a test tube and add 10cm³ of distilled water

(c )      (i)        To 2cm³ of solution F above add 3 drops of bromine water

(ii)       To 2cm³ of solution F add 3 drops of acidified K₂Cr₂O₇.

(iii)      To 2cm³ of solution add 0.1g of sodium hydrogen carbonate provided

(iv) To 2cm³ of solution F add 3 drops of universal indicator and determine the pH.

You are provided with a solid E.  Carry out the following tests and write down your observations and inferences in the spaces provided.

(a) Place half of the solid E in a dry test tube and heat.  Test any gases produced using litmus papers.

(b)       Add about 10cm³ of distilled water to the remaining solid in a test tube and shake. 

Divide the solution into 3 portions.

(i)        To the first portion, add barium nitrate about 1cm³ and about 2cm³ of dilute nitric (V) acid.

(ii)       To the 2^nd portion, add ammonia solution dropwise till in excess.

(iii)      To the 3^rd portion, add 3 drops of potassium iodide solution.

You are provided with:

            - Solid Q a metal carbonate X₂CO₃

            - Solution P hydrochloric acid

            - Solution R, 0.3M sodium hydroxide

You are required to:-

-Prepare a dilute solution of hydrochloric acid and determine its concentration.

-Determine the solubility of solid Q in water.

Procedure:

(a) Place all solid Q in 250ml dry beaker.  Add 100cm³ of distilled water.  Using a glass rod, stir the mixture thoroughly for about two minutes.  Leave the mixture to stand and proceed with steps (b) and (c )

(b) Using a pipette place 25cm³ of solution P in 250ml volumetric flask.  Add about 200cm³ of  distilled water to make upto the mark.  Label this as solution S.

(c) Fill a burette with solution R.  Using a pipette place 25cm³ of solution S into 250cm³ conical flask. Add two drops of the indicator provided and titrate solution S against solution R.  Record your results in table I.  Repeat the titration two more times and complete table I.  (Retain the remaining solution S for use in step (e).

(d) Filter the mixture obtained in step I using a dry filter funnel into a dry conical flask.  Label the filtrate as solution Q.

(e) Clean the burette and fill it with solution S.  Using a pipette transfer 25cm³ of solution Q into a 250cm³ conical flask. Add two drops of the indicator provided and filtrate solution Q with solution S.  Record your results in table II.  Repeat the titration two more times and complete table II.

                                                                                                                (4mks)

Questions:

(a)       Calculate:

(i) Average volume of solution R used.                                                    (1 mark)

(ii) Moles of sodium hydroxide in the average volume of solution R used.            (1 mark)

(iii) Moles of hydrochloric acid in 25.0cm³ of solution S .                            ( 1 mark )

(iv) The molarity of hydrochloric acid solution S.                                         ( 1 mark)

                                                                                                                  (4mks)

(b) Calculate

            (i) Average volume of solution S used.                                             (1 mark )

            (ii) Moles of hydrochloric acid in the average volume of solution S used.   (1 mark )

            (iii) Moles of the metal carbonate; solid Q in 25cm³ of solution Q.              (2 marks )

            (iv) The solubility of the metal carbonate solid Q in water (Relative formula mass of

       metal carbonate = 74 assume density of solution is 1g/cm³ )       (2 marks )

You are provided with the following:

            i)         Solution M which is 0.2 M sodium hydrochloric acid.

            ii)        Solution N which is a Hydrochloric acid

            iii)       1.0g solid X which is a carbonate F₂CO₃.

            You are required to:

                        - Standardize solution N

                        - Determine the RAM of F in F₂CO₃.

            Procedure:

- Fill the burrete with dilute Hydrochloric acid ( Solution N)

-  Pippete 25cm³ of sodium hydrotide solution M into a conical flask

- To this solution and 2-3 drops of methyl orange indicator

- Titrate this solution with solution with solution N and record your result in table I below. Repeat the procedure two more times to complete the table.

                                                                                                                        (3 mks)

a)         i)         Determine the average volume of solution N used.   (1 mk)

            ii)        How many moles of sodium Hydroxide are there in 25cm³ of solution M used.    (1 mk)

            iii)       Calculate the concentration of HCl (solution N) in moles per dm³                               (1 mk)

Procedure II

- Measure 100cm³ of Hydrochloric acid(solution N) into a clean beaker. Put all solid X in the beaker containing 100cm³ of solution N. Leave the acid to react with solid X for 3 minutes.

- Label the resulting solution as L.              

- Fill the burette with solution L.

- Titrate this solution with 25.0 cm³ portions of sodium Hydroxide solution M.

- In the conical flask using methyl orange indicator. Repeat the procedure to complete the table II below.         

                                                                                                                                                                                                         ( 3 mks)

b)         i)         Calculate the average volume of solution L used.                                           (1 mk)

                        ii)        Find the number of moles of solution L in the average volume.                          (1 mk)

                        iii)       Find the number of moles of solution L in 100cm³.                                        (1 mk)

                        iv)       Number of moles of Hydrochloric acid in the original solution N.                          (1 mk)

                        v)         Find the number of moles of HCl which reacted with solid X (F₂CO₃)             (1 mk)

                        vi)       Find the number of moles of solid X which reacted with acid.                          (1 mk)

vii)      Find the reactive molecular mass of solid X and hence the relative atomic mass of F.                                                                   (2 mks)

You are provided with the following:

            i)         Solution D, which is 2 M Hydrochloric acid

            ii)        Solution B, which is 0.1 M sodium Thiosulphate (Na₂S₂O₃)

You are required to find out the effect of change of temperature on the rate of reaction between Sodium thioslphate and hydrochloric acid.

NB: The end result of this reaction is the formation of a yellow/ white precipitate of colloidal sulphur.

Equation:

Na₂S₂O₃(aq)    + HCl(aq) ---------->   S(s)   + SO₂(g)  + 2NaCl(aq) + H₂O(l)

                        Procedure:

            i)         Measure 5 cm³ of solution D into a clean 100cm³ glass beaker.

ii)        Place it together with its contents on a white piece of paper with the word CHEM written on it in bold print.

iii)       Measure the temperature of the solution D

iv)       Record it as shown below in the Table

v)         Measure 100cm³ of solution B

vi)       Add this to the contents of the beaker in(i) above set off the stop watch or clock immediately.

vii)      Record the time taken for the printed word CHEM to become invisible when viewed above the reaction mixture in the 100cm³ beaker

viii)     Thoroughly wash the beaker used in (i) above

ix)       Repeat the experiment using HCl solution D at the temperature indicated in the table.

                                                                                                                          (6mks)

Questions:

On the grids provided plot a graph of:

                        i)         Time (sec) on x axis against Temperature ⁰C y axis

ii)            Recipricoal of time 1/t s^-1 x axis against Temperature ⁰C (y axis)                (3 mks)

b)         Comment on the effect of change of temperature on the rate of the reaction between sodium thiosulphate and hydrochloric acid.

c)         Use the graph of temperature against the recipricoal of time in a) (ii) above to estimate the time that the reaction would take at 58 ⁰C

d)         Use the graph of time against temperature in a(i) bove to calculate the rate of reaction at 43⁰C