Halogens activity series

Try the following problems to practise using the metal and halogen activity series to predict whether reactions will occur. 

Based on what you know about the electronegativity and electron affinity for the halogens, explain the organization of the halogen activity series. 

In the second reaction, chlorine is more reactive than bromine because bromine is listed below chlorine in the halogen activity series. 

Halogen reactivity decreases as one goes from top to bottom in the periodic table, because of the decreasing electronegativity. Therefore, a separate activity series for the halogens can be developed ... 

There are several examples of haloperoxidases containing metals other than iron, and many of these are non-heme enzymes. For example, a series of bromoperoxidases have been isolated recently from seaweed17,18 and an actinomycete19 that require vanadium for halogenating activity. 

The activity series for halogens directly mirrors the position of halogens in the periodic table. It can be shown simply in the following way. Fluorine is the most reactive, and iodine is the least reactive. 

In the same way as you used the activity series for metals, you can use the activity series for halogens to predict whether substances will undergo a single displacement reaction. For example, fluorine is above chlorine in the activity series. So, given the reactants fluorine and sodium chloride, you can predict that the following reaction will occur ... 

Using the activity series for halogens, write a balanced chemical equation for each single displacement reaction. If you predict that there will be no reaction, write NR . 

Describe how to use the activity series of metals and the activity series of halogens. 

Refer to Appendix A for a more complete activity series of metals and of halogens. 

An activity series, similar to the series shown here for various metals and halogens, is a useful tool for determining whether a chemical reaction will take place and for determining the result of a replacement reaction. 

Relate any periodic trends that you identify among the halogens to the activity series of halogens shown in Figure 10-10. 

One element displaces another from a compound Element + compound — element 4 compound Activity series (Table 4-12) summarizes metals and hydrogen halogen activities (Group VIIA) decrease going down the group... 

Halogen Displacement. Another activity series summarizes the halogens behavior in halogen displacement reactions ... 

Displacing One Element by Another Activity Series As we said, displacement reactions have the same number of reactants as products. We mentioned doubledisplacement (metathesis) reactions in discussing precipitation and acid-base reactions. The other type, single-displacement reactions, are all oxidation-reduction processes. They occur when one atom displaces the ion of a different atom from solution. When the reaction involves metals, the atom reduces the ion when it involves nonmetals (specifically halogens), the atom oxidizes the ion. Chemists rank various elements into activity series—one for metals and one for halogens— in order of their ability to displace one another. 

The activity series of the halogens. Reactivity decreases down Group 7A(17), so we can arrange the halogens into their own activity series ... 

A metal will not always replace another metal in a compound dissolved in water because metals differ in their reactivities. Reactivity is the ability to react with another substance. An activity series of some metals is shown in Figure 9.13. This series orders metals by reactivity with other metals. Single-replacement reactions are used to determine a metal s position on the list. The most active metals are at the top of the list. The least active metals are at the bottom. Similarly, the reactivity of each halogen has been determined and listed, as shown in Figure 9.13. 

Activity series of metals and halogens can be used to predict if single-replacement reactions will occur. 

The following reactions (note that the arrows are pointing only one direction) can be used to prepare an activity series for the halogens ... 

Br2(aq). (b) Relate the positions of the halogens in the periodic table with their locations in this activity series, (c) Predict whether a reaction occurs when the following reagents are mixed Cl2( 7) and KI( 7) Br2( 7) and LiCl([Pg.147]

Activity series rank elements in order of ability to displace each other. A more reactive metal can displace (reduce) hydrogen ion or the ion of a less reactive metal from solution. A more reactive halogen can displace (oxidize) the ion of a less reactive halogen from solution. 

---