Science Notes 2 PDF

Acids and Bases and Neutilization Reactions...

Acids and Bases and Neutilization Reactions acids bases · Many familiar compounds a re or · Classification as acid or base is based on chemical composition If you know compound's chemical formula , you may be able to identify it as an acid/base ↳ a very dangerous * · Acids and bases can be ↳ They can be very corrosive (in the case of a strong acid) or caustic (in the case of a strong base) ↳> NEVER try to identify an acid or base by taste or touch PH Scale * of acids and bases is measured on the pl scale the strength of acidic solution : zerorless than 7 · pH an ↳ The more acidic a solution the closer its put is to 0 , · put of a neutral solution : 7 · put of a basic solution : more than 7-14 ↳ The more basic a solution, the closer its pH to 14 3 is 16 =1000 times more acidic than solution with A solution with plt & a potc pH Indicators indicators chemicals that colour depending on the acidity/basicity of the solution in which they are placed · DH are change Blue = basic acidic ↳ litmus paper : Red = · Indicators change colour at different ph values , so different indicators are used to identify different plt values ↳ bromothymol blue for plt 6-1 6. for plt 8 2-10 ↳ Phenolphathalein. ↳ many natural sources (ie beets. and cabbage) are indicators Acids aqueous , they often must be dissolved in water to behave like acids · Acids are often written with subscript (aq) = since · The chemical formula of an acid usually starts with hydrogen (H) nitric acid HP (aq) Hydrochloric acid = eg. = HNOz (aq)  Acids cont. · Acids with a carbon usually have the written first 100 acid HCH , acetic CHzCOOH car = = (a) ic) Naming ide to Acids I when naming acids change fluoride hydrofhoric acid. hydrogen 1 + = of matter is given start the name with "hydrogen HF-hydrogen fluoride - > if no state HF (aq) = hydrofivoric doid + carbonate = carbonic acide ide- > hydro-is acid 2. hydrogen acid HzCOz = hydrogen Carbonate ate-ic acid acid # zlOzcaa) Carbonic ite--ous = sulphurous acid. 3 hydrogen + sulphite = H Soz = hydrogen Sulphite Hy Soz(aq) = sulphurous acid = Some "common" Acids Hydrobromic Chloric acid acid HNOz(aq) - nitric acid suphuric acid H2SO4 caal - acid HzPOy(aal-Phosphoric (aa) acid Az(Ob - carbonic Naming Acids. 1 Binary Acids composed of hydrogen and one hon-metal other element ↳ of of non-metal + ic dcid Hydrotbase name ↳ Examples · HC : Hydrochloric acid HBr : acid o hydrobromic · HF : hydrofluoric acid Oxyacids (contain oxygen) ↳ consist of hydrogen , oygen , and another element lusually a non-metal). The name the acid depends on the polyatomic ion in ions ends in late it switches to i ↳ If the polyatomic It switches to "ors" " If ion ends in "ite. - > the polyatomic ↳ Do not use hydro in oxyacial names L- Examples o H2SOy (sulfate-sulfuric acid) o He S03 (sulfite - > sulfurous acid) (nitrate > hitric acid) HNO3 - ·  Bases Bases subscript (cal often must be dissolved in water to behave like bases ageous, they = · Bases are often written with since o The chemical formula of a base usually ends with hydroxide (OH) o Examples of common bases 4) NaOH (aa) - > Sodium Hydroxide ↳ Mg(OH) < (aq) - > Magnesium Hydroxide > (a(OH) zeng) -> Calcium Hydroxide ↳ NHyOH (aq) - > Ammonium Hydroxide Production Fons of coduct electricity because they ions in solution Acids and bases can release · Acids release At cas ions release OH ions · Bases las refers to the concentration of ions it has The put of a solution Square brackets signify concentration : [Htnal) , [OHiaal] · High [Hiaal] = low ph , very acidic basic · High /ottiaal) = highpH , very solution cannot be both acidic and basic at the same time. other, so a with Ht and Of ions readily react each cancel each other out and form water in a process called neutralization They + OH · H + can) jag) - > Hz0c) Properties of Bases * lab in your morth) put anything from the bitter (*never science · taste ** never touch chemicals with your bare skin) feel Slippery ( ** · bases a re caustic-burn skin o Many o no reaction with metal o conduct electricity · have a pl greater than 7 blue · turn red litrus payer in basic solution · Phenolphthalein is pink  solution · formO f coal (hydroxid) ions in of base usually ends with OH · chemical formula a Properties of Acrels · taste sour (never put anything from the science lab in your mouth) acids corrosive - burn skin ** and "eat through metal" ( * * never touch chemicals with your bare skin · many are · Conduct electricity · have a pl less than < · turn blue litmus paper red · phenolphthalair is colorless in an acidic solution solution · form H* (g) (hydrogen) ions in formula of acid usually starts with I · Chemical an Acid - Base Neutralization reactions acid and salt and water Neutralization occur when an a base react to produce a base salt-water acid + > - HY + MON - > MX + H, 0 EX. H(cal + NaOAcaal - > Nacis) + #20 cas) Salt water -ve ion acid base ↳ X reprsents a ion ↳ M reprsents a the balanced equation for each rxn- > reaction Write a. Sulphuric 1 acid is used to neutralize calcium hydroxide H2SO4caa) + CalOHz- > CaSOy +IH , O. 2 Phosphoric acid helps to neutralize iron (11) hydroxide , one of the compounds that causes rust FeLOA) > - FePOy + TH2O H2PO4 (a) +