Name………………………………………………………. Date…………………………….
QUESTION 1
You are provided with the following:
● Solution A: containing 2.95g dibasic acid, H2X in 250 cm3 of solution.
● Solution B: containing 4g of sodium hydroxide in 500 cm3 of solution.
You are required to determine the value of X in the formula of the acid A.
Procedure
Fill the burette with solution A. Using pipette and pipette filler, place 25cm3 of solution B in a conical flask.
Add two drops of phenolphthalein indicator and titrate with solution A. Fill the table below. Repeat the titration
two more times and record the results
Titration I II III
Final burette reading (cm3) 40.3 20.8
Initial burette reading (cm3) 0.0 20.7
Volume of solution A used (cm3) 20.7 20.8
a. Determine the average volume of solution A used (1mk)
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b. Determine the molarity of sodium hydroxide solution (3mk)
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c. Calculate the number of moles of sodium hydroxide in the 25cm3 used (3 mks)
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d. Write the equation of the reaction between acid A (dibasic Acid) and sodium hydroxide. (1mk)
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e. Determine:
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i. The number of moles of acid A in the average volume used. (3 mks)
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ii. The molarity of acid A (3mks)
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iii. The molar mass of the acid A. (2mks)
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f. Determine the mass of X in one mole of the acid. (H= 1.0) (3mk)
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QUESTION 1
You are provided with solids M, N and P. Carry out the following tests and write your observations and
interferences in the spaces provided.
TESTS ON SOLID M
Procedure Observation Inference
a. Place all of solid M in a solid dissolves to form a
boiling tube. Add 10cm3 of colourless solution.
distilled water and shake
thoroughly. Label the
resulting mixture M.
b. To about 2 cm3 of M in white precipitate formed
a test tube, add 2M dissolves in excess
sodium hydroxide
solution drop wise until
in excess.
