Day 13– Naming Acids & Bases Sci 10 Chemistry

What is an Acid?  Acid: a compound that makes hydrogen ions H + (aq) when dissolved in water i.e.: HCl (aq) → H + (aq) + Cl - (aq) Note: acids must be dissolved in water to produce H + ions. Look for the (aq) which means aqueous to indicate the acid is dissolved in water How to identify them: Hydrogen + a non-metal with the (aq) symbol

What is a Base?  Base: a compound that makes hydroxide ions OH - (aq) when dissolved in water i.e. NaOH (aq) → Na + (aq) + OH - (aq) How to identify them: Metal + hydroxide ion (OH) with the (aq) symbol

Naming Bases  Easy! Name the cation followed by the anion (hydroxide) with the ending –ide (just like we’ve been doing all along with ionic compounds)  You will know that it is a base if you see the (aq)  i.e. NaOH (aq) sodium hydroxide  i.e. Ca(OH) 2 (aq) calcium hydroxide

Try It! Name the following base: 1. KOH (aq) potassium hydroxide

Naming Acids with A Non- Metal (simple anions)  i.e. HCl (aq)  You will know to name this as an acid because of the (aq) 1. Write “hydro-” 2. Add the name of the non-metal (shortened, with the ending “-ic”) i.e. chloric 3. Add the second word “acid” HCl (aq) = hydrochloric acid

Try It!  Name the following acids: HF (aq)  hydrofluoric acid HBr (aq)  hydrobromic acid HI (aq)  hydroiodic acid

Naming Acids with Polyatomic Ions  The first part of the name is the name of the polyatomic ion which is shortened. One of two endings are added to this name. - ic if the anion name ends in - ate. - ous if the anion name ends in - ite.  The last part of the name is acid  i.e. HNO 3(aq) (nitrate ion) = nitric acid  i.e. HNO 2(aq) (nitrite ion) = nitrous acid

Try It!  Name the following acids:  H 2 CO 3 (aq) carbonic acid  H 2 SO 4 (aq) sulfuric acid (sulfate ion)  H 2 SO 3 (aq) sulfurous acid (sulfite ion)

Name to Formula  Determine the anion present from the name: “hydro” in the name means H plus a non-metal “-ic” or “-ous” means H plus a polyatomic ion  The cation (positive ion) is always H +  Write down the formulas of the two ions. Draw the table to see which subscripts to add:  i.e. sulfuric acid  sulfuric > sulfate > SO 4 2-  acid > hydrogen > H 1+  H SO 4  Formula > H 2 SO 4 (aq)

Try It!  Write the formula for: phosphoric acid Anion = phosphate PO 4 3-, Cation = H 1+ H PO Formula: H 3 PO 4(aq)

To Do Day 13 Practice p. 165 #18, 20