1. Double Replacement Prediction I can predict the two products that will be created from a double replacement reaction

2. Identification from Reactants Two compounds

3. Prediction of Products Switch the anions First with the last, inside back – Like FOIL in math. ALWAYS put the CATION FIRST

4. Iron (III) hydroxide + sodium phosphate Write the formulas for the reactants

5. Iron (III) hydroxide + sodium phosphate Fe +3 (OH - ) 3(aq) + Na + 3 PO 4 -3 (aq)  Predict the products

6. Iron (III) hydroxide + sodium phosphate Fe(OH) 3 + Na 3 PO 4  Fe +3 PO 4 -3 + Take the subscript along because it is part of what makes phosphate phosphate. Phosphate is PO 4 -3 First with last

7. Iron (III) hydroxide + sodium phosphate Fe(OH) 3(aq) + Na 3 PO 4(aq)  FePO 4 + Na + OH - Put the cation first and then the anion. Balance their charges. Do not carry along these subscripts! They are here to balance the charges in these compounds. Inside, back

8. Iron (III) hydroxide + sodium phosphate Fe(OH) 3(aq) + Na 3 PO 4(aq)  FePO 4 + NaOH Now balance equation: Because 3 OH as reactants need 3 NaOHs That gives 3 Na as products, which we have as reactants 3

9. Iron (III) hydroxide + sodium phosphate Fe(OH) 3(aq) + Na 3 PO 4(aq)  FePO 4 + NaOH 3 Iron (III) phosphate and sodium hydroxide

10. Aluminum sulfide + hydrochloric acid Write the formulas for the reactants

11. Aluminum sulfide + hydrochloric acid Al +3 2 S -2 3 + H + Cl -  Predict the products

12. Aluminum sulfide + hydrochloric acid Al 2 S 3 + HCl  Al +3 Cl - 3 + Do not carry along this subscript! It is here to balance the charges in this compound. First with last

13. Aluminum sulfide + hydrochloric acid Al 2 S 3 + HCl  AlCl 3 + H + 2 S -2 Do not carry along this subscript! It is here to balance the charges in this compound. Put the cation first and then the anion. Balance their charges. Inside, back

14. Aluminum sulfide + hydrochloric acid Al 2 S 3 + HCl  AlCl 3 + H 2 S Now balance: Have 2Al as reactants, need 2 AlCl 3 Have 3 S as reactants, need 3 H 2 S That gives us 6 H and 6 Cl on the product side so need 6HCl Al 2 S 3 + 6HCl  2AlCl 3 + 3H 2 S

15. Aluminum sulfide + hydrochloric acid Al 2 S 3 + 6HCl  2AlCl 3 + 3H 2 S Produces aluminum chloride and dihydrogen monosulfide

16. Homework Complete the double replacement prediction worksheet.