Double Replacement Reactions
General Equation AX + BY AY + BX
Helpful Hints Three types of substances can be produced from a double replacement reaction 1. Solid (S) 2. Liquid ( l ) or solution (aq) 3. Gas (g) CO 2 H 2 S HCN H 2 CO 3 becomes CO 2 (g) + H 2 O ( l ) If both products are aqueous then there will be no reaction **Most common, need to know
Steps to predicting a double replacement reaction 1. Rewrite the cations 2. Switch the anions 3. Check to make sure new compounds are neutral 4. Check solubility of each new compound (use chart provided)
How to read the solubility chart 1. Find the anion from your compound 2. Match the cation 3. Either soluble (aq) or not soluble (s) Example: Na 3 PO 4 soluble (aq) (see chart of next page)
AgNO 3 + NaCl ______________ Example 1: Step 1: Ag + Na Step 2: AgCl + NaNO 3 Step 3: Ag +1 Cl −1 (charges balance; neutral) Na +1 NO 3 −1 (charges balance; neutral) Step 4: Look at the solubility chart (next slide) AgCl not soluble (S) NaNO3 soluble (aq) AgCl (s) + NaNO 3 (aq)