vs Nonelectrolytes Electrolytes vs NonElectrolytes Electrolyte NonElectrolyte When dissolved in water allows for electron flow When dissolved in water does not allow for ID: 1031370
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1. Solutions Review Pt 2Electrolytes vs Non-electrolytes
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3. Electrolytes vs Non-ElectrolytesElectrolyteNon-ElectrolyteWhen dissolved in water, allows for electron flowWhen dissolved in water, does not allow for electron flowProduces ions when dissolved in waterDoes not produce ions when dissolved in waterSubstances which were formed by ionic bondsSubstances which were form by covalent bondsAcids, bases and saltsNote: for a substance to conduct electricity, it must be dissolved in water
4. What’s ionic and covalent again? Ionic bond→ bond between a metal and a non-metalThe metal looses electron to get a positive chargeThe non-metal gains electron to get a negative chargeCovalent bond → bond between non-metal sharing electrons to get stable octet
5. Electrolyte dissociationDef: electrolytes are dissolved in water, dissociating from one another to their respective positive and negatively charged ions, allowing for conduction of electricityKey thing → get the production of ions during dissociation!No ions, no electrical conductivity
6. Examples of electrolyte dissociationSaltsNaCl(s)→Na+(aq) + Cl-(aq)CaCl2(s)→Ca2+(aq) + 2Cl-(aq)AcidsH2SO4(s)→2H+(aq) + SO42-(aq)HCl(s)→H+(aq) + Cl-(aq)BasesKOH(s)→K+(aq) + OH-(aq)NaOH(s)→Na+(aq) + OH-(aq)
7. Acids!An acid is a substance that releases H+ ions in an aqueous solutionHow can you tell an acid from molecular formula?Usually an acid starts with H atom and is then followed by a non-metalException! Acetic acid CH3COOH dissociates to H+ andCH3COO-Acids rnx with blue litmus paper and turns it red
8. Bases!A base is a substance that releases OH- ions in an aqueous solutionHow can you tell an acid from molecular formula?Usually a base starts with a metal and is ends with OHException! Ammonia NH3 is actually a base even though it doesn’t have an OH- group!When it reacts with water, the following reaction occursNH3 + H2O → NH4+ + OH-Bases rnx with red litmus paper and turns it blue
9. Salts!A salt is a substance that is produced by chemical bonding of a metal and a non-metal other than H+ or OH-It is an ionic bond!NaCl: Sodium chloride dissociates to Na+ and Cl-KBr: Potassium bromide dissociates to K+ and Br-BeS: Beryllium sulfide dissociates to Be2+ and S2-Litmus paper has no effect on salts
10. Types of ElectrolytesAcidsBasesSaltsDefinitionSub. that when dissociate release H+ in sol.Sub that when dissociate release OH- in sol.When dissociate have metal and non-metalLitmus Paper TestTurns blue paper redTurns red paper blueDoes not rnxUses/Found inNeutralizes base, found in fruitsNeutralizes acid, found in blood, cleaning prodsFound in fertilizers, soaps, How to recognizeUsually starts with H, has H+ grUsually ends with OH, has OH- gr1st = metal2nd= non-metalExamplesHCl, HF, HNO3NaOH, Ca(OH)2 NaCl, AgNO3Exceptions to “H” ruleWater, Acetic Acid (CH3COOH)CH3OH, C2H50H -> alcohols!; Not bases, NH9 is a base
11. pH ScaleUsed to determine whether or not a substance in solution is an acid, a base, or neutralGoes from 0 to 140-6.9 → acidsStrong acids closer to 0Weak acids near 6.97.1-14 → basesStrong bases closer to 14Weak bases near 7.1
12. pH ScaleThe scale goes up by a 10-fold factorMeaning if you are comparing an acid with a pH 2 and pH of 3, the acid which has a pH 2 is 10 times strongerIf you are comparing an acid with pH 2 and pH 6, the acid which has pH 2 is 104 times stronger
13. How to i.d if you have an acid, base or neutral substanceLitmus Paper TestTells you if your substance is an acid, base or neutralBuffer Solution + IndicatorsA buffer solution is a solution composed of a weak acid and it’s associated base. Key: it’s pH changes very little when strong acid/base added to it, meaning it has specific pH levels!An indicator is a chemical which undergoes a colour change at specific pHs
14. Litmus Paper TestBlue paperTurns red when introduced to an acidStays blue when introduced to a base or a neutral solutionRed paperTurns blue when introduce to a baseStays red when introduce to an acid or a neutral solution
15. Buffer Solution + IndicatorThis procedure plays on the specificity of buffer solutionsThe first step you do is introduce your solution to the indicator and record that colourThen you introduce your indicator to buffer solutions ranging from pH 1 to pH 14 and match the colourYou may have to use more than one indicator, for their ranges overlap, thus allowing to get a more precise pH value!
16. pH indicator examplepH12345678910111213Thymol Blue Red Yellow BlueBromo. Blue Yellow PurpleMethyl Red Red YellowPhenol Red Yellow RedCresol Red Yellow Reddish-PurplePheno. Colourless FuchsiaThymol. Colourless Blue
17. pH indicator exampleWhich indicator(s) would you use to find a strong acid? Strong base? Neutral substance?My solution turned red using Methyl Red and purple using Bromophenol Blue. What’s the pH of my solution (range)?My solution turned blue using Thymol Blue and fuchsia using Phenolphthalein. What’s the pH of my solution (range)?
18. Mnemonic to remember for acids and basesAcids are red, bases are blue, water is neutral, what about you?Acid → turn blue litmus paper redBases → turn red litmus paper blueWater → as a neutral substance, does not rnx with litmus paper (same as salts)