AL Chemistry Experiment Report Sheet

Experiment 25, 26, 27: Investigating the Properties of Halogens

1. The Solubility of the Halogens in Organic Solvents

2. Reaction of Halides in Solution

3. Reactions of Solid Halides

 

Name: ___________________ (       )                                                Form 7 S

 

Results Table 25: Solubility of halogens in organic solvents

	Nature of each layer	Chlorine water	Bromine water	Iodine solution
Colour of aqueous solution	-------
Colour of each layer after shaking with   ____________	Upper layer (org / aq)
	Lower layer (org / aq)
Colour of each layer after shaking with   ____________	Upper layer (org / aq)
	Lower layer (org / aq)
Colour of each layer after shaking with   ____________	Upper layer (org / aq)
	Lower layer (org / aq)

 

Questions:

1.    Do you think the halogens are more soluble in the organic solvents then in water? Explain.

 

      _____________________________________________________________________

 

      _____________________________________________________________________

 

      _____________________________________________________________________

 

2.    Which of the three halogens has a significantly different colour in the organic layer from its colour in the aqueous layer?

 

      _____________________________________________________________________

 

3.    How would you distinguish, other than by smell, between a dilute aqueous iodine solution and a fairly concentrated solution of bromine water?

 

      _____________________________________________________________________

 

      _____________________________________________________________________

Results Table 26: Reaction of halides in solution

Test	Chlorine water	Bromine water	Iodine solution
Action of AgNO3(aq)
Effect of standing in (a) dark (b) light
Action of AgNO3(aq) followed by dil. HNO3(aq)
Action of AgNO3(aq) followed by NH3(aq)
Action of Pb(NO3)2(aq)
Action of H2O2(aq) and dil. H2SO4(aq)

Questions:

1.   Write ionic equations for the reactions between each of the three halide solutions and

      (a)  silver nitrate solution.

 

      _____________________________________________________________________

 

      (b)  lead(II) nitrate solution.

 

      _____________________________________________________________________

 

2.   What chemical tests would you perform in order to distinguish between

      (a)  chloride and bromide

 

      _____________________________________________________________________

 

      _____________________________________________________________________

 

      (b)  bromide and iodide

 

      _____________________________________________________________________

 

      _____________________________________________________________________

 

3.    (a)  Write an ionic equation for the reaction between an aqueous iodide and acidified

hydrogen peroxide.

 

      _____________________________________________________________________

 

(b)  Why do you think no reaction occurs between acidified hydrogen peroxide and the other halide ions?

 

      _____________________________________________________________________

 

      _____________________________________________________________________

 

      _____________________________________________________________________

 

4.    Suggest a reason for the darkening effect of light on the silver chloride and silver bromide precipitates.

 

      _____________________________________________________________________

 

      _____________________________________________________________________

 

      _____________________________________________________________________

 

 

 

 

Results Table 27: Reaction of solid halides

Test	Chloride	Bromide	Iodide
Action of conc. H2SO4 and MnO2
Observations
Suspected product(s)
Confirmatory tests
Action of conc. H2SO4
Observations
Suspected product(s)
Confirmatory tests
Action of H3PO4
Observations
Suspected product(s)
Confirmatory tests

Questions:

 

1.   Complete and balance the following equations:

(a)        KCl(s)    +          H₂SO₄(l) ¾®     ___________________________________

(b)        KCl(s)    +          H₃PO₄(l) ¾®     ___________________________________

(c)        KBr(s)   +          H₂SO₄(l) ¾®     ___________________________________

            HBr(g)   +          H₂SO₄(l) ¾®     ___________________________________

(d)        KBr(s)   +          H₃PO₄(l) ¾®     ___________________________________

(e)        KI(s)     +          H₂SO₄(l) ¾®     ___________________________________

            HI(g)    +          H₂SO₄(l) ¾®     ___________________________________

(f)         KI(s)     +          H₃PO₄(l) ¾®     ___________________________________

 

2.   Explain the reactions between potassium chloride and concentrated sulphuric acid, with and without manganese(IV) oxide.

 

      _____________________________________________________________________

 

      _____________________________________________________________________

 

      _____________________________________________________________________

 

      _____________________________________________________________________

 

      _____________________________________________________________________

 

      _____________________________________________________________________

 

      _____________________________________________________________________

 

3.   Why does the addition of manganese(IV) oxide appear to have little effect on the reaction between potassium iodide and concentrated sulphuric acid?

 

      _____________________________________________________________________

 

      _____________________________________________________________________

 

      _____________________________________________________________________

 

      _____________________________________________________________________

 

      _____________________________________________________________________

 

The End