Most reactive F 2 > Cl 2 > Br 2 > I 2 Least ReactiveĮlements higher on the list (alkali metals) replace those lower on the list (like the noble metals) in single replacement reactions.
REACTIVITY DEFINITION CHEMISTRY SERIES
Use the reactivity series to determine whether a single replacement reaction will occur.įor anion replacement, the reactivity series for the halogens is: Then, adjust the coefficients in front of the reactants and products to balance the chemical equation:ģ Mg(s) + 2 AlPO 4(aq) → 2 Al(s) + Mg 3(PO 4) 2(aq) Using the Reactivity Series to Predict Whether a Reaction Will Occur However, the aluminum cation has a charge of +3 (balancing the PO 4 3- anion), while the magnesium ion (as a rare earth metal) has a charge of +2.įirst, find the formula of the product by balancing the cation and anion charges to get: Magnesium is more reactive than aluminum, so the replacement is favorable. You may need to balance the charge of the cation and anion and then balance the chemical equation to get what you need. The two cations don’t always have the same oxidation state. All halogens have the same oxidation state (-1), so it’s a simple substitution.īut, if the elemental reactant is not a halogen, it replaces the cation in the compound.
If the pure element is a halogen, it takes the place of the other halogen in the compound. The product of a single replacement reaction is easy enough to predict.
REACTIVITY DEFINITION CHEMISTRY HOW TO
I 2 + 2 KBr → no reaction How to Determine the Products of Single Replacement Reactions For example, the following reaction does not occur: Examples of anion replacement reactions include:Īgain, if the elemental reactant is not more reactive than the other anion, no reaction will occur. In addition to being a single replacement reaction, this is also an oxidation-reduction or redox reaction. In practice, the only anions participating in single replacement reactions are the halogens (fluorine, chlorine, bromine, iodine). Instead of cation replacement, a single replacement reaction may involve the anion. In some cases, the reverse reaction is favored, but the forward reaction is not.
This entry was posted on Decemby Anne Helmenstine (updated on December 2, 2021)Ī single replacement reaction or single displacement reaction is when one element replaces another in a compound.