INSTRUCTIONS TO CANDIDATES
 Answer ALL questions in the spaces provided in each question.
 Mathematical tables and electronic calculators may be used for calculations.
 all working must be clearly shown where necessary.
 You are provided with
 2.0M NaoH solution labelled B
 Sulphuric(VI) acid solution labelled A `
You are to: Prepare a dilute solution of NaoH solution.
 Determine the concentration of in moles per litre.
PROCEDURE 1 Using a pipette 25.0cm^{3} of solution B and place it into 250cm^{3} volumetric flask.
 Add about 200cm^{3} of distilled water and share well.
 Add more water to make up to 250cm^{3 }mark. Label this solution C
 Calculate the concentration of the dilute solution C in moles per litres. [2mks]
PROCEDURE 2 Fill the burette with solution A and record the readings in the table below.
 Pipette 25cm^{3} of dilute solution C and place it into 250ml conical flask.
 Add 23 drops of phenolphthalein indicator.
 Titrate with solution A.
 Record your results in the table below.
 Repeat the titration two or more times and complete the table.
I II III Final burette reading (cm^{3}) Initial burette reading(cm^{3}) Volume of solution A(cm^{3})  Determine average volume of the acid (solution A) used. [1mk]
 Determine moles of dilute solution C in the volume used. [2mks]
 Write an equation for the reaction taking place. [1mk]
 Determine the number of moles of A used. [2mks]
 Determine the concentration of A in moles per litre. [2mks]
 Calculate the concentration of the dilute solution C in moles per litres. [2mks]
 You are provided with the following
 2M sodium hydroxide solution, solution B
 2M hydrochloric acid, solution D
You are required to determine the molar enthalpy of neutralization of the acid using sodium hydroxide.
PROCEDURE Measure out 20cm^{3} of acid into a clean plastic beaker.
 Record the temperature of this solution in the table below
 Measure 5cm^{3} of sodium hydroxide and add it to the hydrochloric acid.
 Stir with the thermometer and record the maximum temperature reached.
 Repeat the above procedure adding 5cm^{3} portions of sodium hydroxide until the total volume of the solution is 50cm^{3}.
Volume of acid(cm^{3}) 20 20 20 20 20 20 20 Volume of NaoH added cm^{3} 0 5 10 15 20 25 30 Temperature(°C)of solution
You are required to: Plot a graph of temperature rise against sodium hydroxide added. [3mks]
 From your graph determine:
 maximum temperature change. [1mk]
 the volume of NaOH that is required for complete neutralization [1mk]
 Calculate the molar enthalpy of neutralization for this reaction. (C=4.2J/g/K) assume density of solution is 1gcm3) [2mks]
 The theoretical molar heat of neutralization is 57.2kj/mol1.Compare your value in [ii] above with the theoretical value. Give the reasons for any differences noted between these two values. [2mks]
 Plot a graph of temperature rise against sodium hydroxide added. [3mks]
 You are provided with solid N carry out the tests below and record your observations and inferences.
 Place a spatula of N in a test tube and add 5cm3 of water and shake well divide the solution in to three portions.
OBSERVATION (2mks) INFERENCE (1mk)  Add sodium hydroxide to the first portion drop wise while observing till in excess
OBSERVATION (2mks) INFERENCE (1mk)  Add ammonia solution to the second portion drop wise until in excess.
OBSERVATION (2mks) INFERENCE (1mk)  Add four drops of potassium iodide solution to the third portion.
OBSERVATION (2mks) INFERENCE (1mk)  Add three drops of acid barium nitrate to the fourth followed by 5 drops of nitric acid.
OBSERVATION (2mks) INFERENCE (1mk)
 Place a spatula of N in a test tube and add 5cm3 of water and shake well divide the solution in to three portions.
CONFIDENTIAL
 Burette
 Pipette
 2 conical flasks
 120cm^{3 }of 2.0M NaoH labelled B
 100cm^{3} 0f 0.2M H_{2}SO_{4} labelledA
 250cm^{3} volumetric flask
 A label
 Pipette filter
 Stand and clamp
 500cm^{3} distilled water
 Phenolphthalein indicator
 100cm^{3} plastic beaker
 Thermometer
 10cm^{3} measuring cylinder
 100cm^{3} measuring cylinder
 50cm^{3} 2.0M HCl , Solution D
 50cm^{3} 2.0M NaoH
 6 test tubes in a test tube rack
 0.2g of solid N (Al_{2}(SO_{4})3]
REAGENTS
 2M NaoH
 2M NH_{4}OH
 Ba (NO_{3}) 2solution
 2M nitric acid
 Potassium iodide solution
MARKING SCHEME
PROCEDURE 1
 2 moles →1000cm^{3 }25 × 1 =0.05 moles
1000
? 25cm^{3}
0.05 moles250cm^{3 }0.05×1000 =0.2m
250
PROCEDURE II
Complete table 1
Decimal 1
Arithmetic 1
Accuracy 1=0.2 12.5+12.5+12.5=12.5cm^{3 }
3  0.2 moles→1000cm^{3 }0.2m × 25=0005 moles
1000
25cm^{3}  2NaoH [aq]+H_{2}SO_{4[aq]}→NaSO_{4[aq]}+2H_{2}O_{[l]}
 Mole ratio
A:C C=0.0025moles
1:2 A=0.005=0.0025 moles
2  0.0025→answer a=0.0025×1000
answer a
1000
 12.5+12.5+12.5=12.5cm^{3 }
 Table
Complete table 1
Decimal point 1
Trend 1 Graph
Axis ½Mk each
Scale½Mk each
Plotting 1 mk
Curve 1 mk 
 answer from the graph
 Use MCDθ
Mass=50×1=50g.
From MCDθ→50g×^{4.2}/_{g} J/g/°C × answer in b [i] above.  Theoretical value is higher than the obtained value
Heat lost to the surrounding[1mk]
Heat absorbed by the apparatus[1mk]
 Graph


Observation Inference It dissolves into[½]a colourless solution[½mk] Soluble salt[½]NoCu^{2+},Fe^{2+} or Fe^{3+}[½ mk] 
Observation Inference White precipitate soluble in excess [1mk] Pb^{2+},Zn^{2+},Al^{3+} ions present[ 2mks] for the 3 
Observation Inference White precipitate insoluble in excess[1mk] Pb^{2+},Al^{3+} ions present[1mk] 
Observation Inference No Yellow precipitate formed[1mk] Pb^{2+} ions absent/ Al^{3+} present[1mk]
Observation Inference White precipitate [1mk]
Don’t dissolve on adding nitric acidSO_{4}^{2}ions[1mk]

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