Single Replacement Reactions

+ +

General Equation

A + BX AX + B

Helpful Hints

Metals replace metals and hydrogen

Halogens replace halogens

If an element can take more than one charge, use the +2 charge

Metals + H2O metalOH + H2

Steps to Predicting a single replacement reaction

1. Look at the reactants given and determine if the single element is a metal or a halogen

2. Look at the compound given in the reactants, and find the same type of element (metal or halogen) identified in step 1

3. Find both elements on the reactivity series

4. If the element identified in step 1 is higher on the reactivity series than the element in step 2, then they will switch places to form new products

5. Look at the products formed • If the single element is a diatomic molecule, it

needs a subscript of 2 • If your compound is not neutral; look at the

charges and add subscripts to make it neutral

Example 1:

Step 1: Zn is the single element, and it is a metal

Step 2: Ag is the metal in the compound

Step 3: Look at the activity series for metals (next slide)

Step 4: Zn is higher on the list (more reactive) so it will switch places with Ag (new products = Ag + ZnNO3

Step 5: Ag is not a diatomic molecule so it doesn’t need a subscript; ZnNO3 is not a neutral compound so we need to look at the charges and make it neutral; Zn2+ NO3

1-

Zn(NO3)2

Zn + AgNO3 ______________Ag + Zn(NO3)2

Activity SeriesMetalsLiRbKCsBaSrCaNaMgAlTiMnZnCrFeCdCoNiSnPbHSbBiCuHgAgPtAu

Most reactive

Least reactive

Cl2 + KI __________Example 2:

Step 1: Cl is the single element, and it is a halogen

Step 2: I is the halogen in the compound

Step 3: Look at the activity series for non-metals (next slide)

Step 4: Cl is higher on the list (more reactive) so it will switch places with I (new products = KCl + I

Step 5: I is a diatomic molecule so it needs a subscript of 2; KCl is a neutral compound because the charges are equal and opposite

KCl + I2

Activity SeriesNon-metalsF2

Cl2Br2

I2

Most reactive

Least reactive

Example 3:

Step 1: Ag is the single element, and it is a metal

Step 2: K is the metal in the compound

Step 3: Look at the activity series for metals (next slide)

Step 4: K is higher on the list (more reactive) so Ag will not switch places with K

Step 5: There will be NO REACTION (NR)

Ag + KNO 3 ______________NR

Activity SeriesMetalsLiRbKCsBaSrCaNaMgAlTiMnZnCrFeCdCoNiSnPbHSbBiCuHgAgPtAu

Most reactive

Least reactive