Predicitng Halogen Reactions?

Question

1) Indicate whether a reaction would occur when you mix aqueous solutions of each of the following two substances.

Yes or No

potassium chloride and bromine.
sodium iodide and bromine.
sodium bromide and iodine.
potassium iodide and chlorine.

2)What is the result of mixing each of the following pairs of reagents?

NaI + Br2

I− + Cl2

KCl + Br2

Answer 1

You are asking which is the better oxidizing agent between Cl2, Br2 and I2. Cl2 is strongest, then Br2 and then I2. So, Cl2 will oxidize Br- and I-, Br2 will oxidize I- and I2 will not oxidize the other two.

1) No, Yes, No, Yes

2) 2NaI(aq) + Br2(l) ---> 2NaBr(aq) + I2(s)
2I-(aq) + Cl2(g) ---> 2Cl-(aq) + I2(s)
KCl(aq) + Br2(l) ---> No Reaction

Answer 2

The relative activity of the halogens is easy to remember since the closer they are to the top of the chart the higher their chemical activity. So, their relative activity is F > Cl > Br > I > At. In your reactions :

2 NaI + Br2 ---> 2NaBr + I2 (Br is above I in activity)

2I - + Cl2 ----> 2Cl - + I2 (Cl is above I in activity)

KCl + Br2 ----> No reaction (Br is below Cl in activity)

Answer 3

1)
No
Yes
No
Yes

2)
2NaI + Br2 ===> 2NaBr + I2
2I- + Cl2 ===> I2- + 2Cl-
KCl + Br2 ===> No reaction

Answer 4

1) No reaction, I2 is less reactive than Br-. 2) Br2 displaces I-. 3) F2 displaces Cl-. 4) Cl2 displaces Br-. 5) No reaction, Br2 is less reactive than Cl-. 6) No reaction, Cl2 is less reactive than F-.

Answer 5

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