Results

 

TITRATION #

 

1

2

3

4

5

Final Reading (mL)

9.45

17.55

27.10

35.20

42.20

Initial Reading (mL)

1.38

9.45

17.55

27.10

35.10

Titre (mL)

8.07

8.10

9.55

8.10

7.10

Questions and Calculations

  • What is meant by the term concordant titres and which of the titres above are concordant?

 

  • Calculate the average volume of the titres shown above. Use this value to calculate the average amount of 0.100 M HCl , in mol, added to each aliquot of diluted ammonia solution.

 

 

  • Write balanced equations for the reaction which occurs between ammonia and hydrochloric acid. Use this equation to calculate the amount of ammonia, in mol, that was present in each 20.00 mL aliquot.

 

  • FULL EQUATION

 

 

  • IONIC EQUATION

 

 

  • Calculate the amount in grams of ammonia in the 20.0 mL aliquot

 

 

 

  • Calculate the amount of ammonia, in grams, present in the 250 mL volumetric flask. (This flask contained all of the ammonia present in the original sample.)

 

 

 

 

 

  • Find the mass of the ammonia present in the original sample. Hence find the percentage by mass of ammonia in the original sample of the household cleaner.

 

 

 

 

 

General questions

  • Give one reason why the result obtained by using a sample from an old, previously opened bottle of the cleaner might be lower than that obtained using a sample from a fresh bottle.

 

 

 

 

  • Ammonia is a gas at room temperature but is extremely soluble in water. Drawing from what you know of the molecular structure of an ammonia molecule explain ammonia's high solubility in water.

 

Consider the burette readings shown on the right.

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