Presentation on theme: "Families of Chemical Compounds – Acids & Bases"— Presentation transcript:
1 Families of Chemical Compounds – Acids & Bases Chapter 9Families of Chemical Compounds – Acids & Bases
2 Flashback – What’s a Chemical Compound? As we have learned, when elements bond together due to ionic or covalent bonding, they form chemical compounds.Different combinations of elements form different compounds.2 of these types of compounds are acids and bases.
3 Properties of Acids Sour tasting Affect indicator colors blue litmus paper turns redphenolphthalein remains colorlessAcids react with active metals to form Hydrogen gas plus a metal compound
4 Properties of AcidsWhen acids are dissolved in water, they produce positive hydrogen ions (H+) (this is a proton)Acids are often known as proton donorsstrong acids dissolved in water produce a lot of hydrogen ions and are good electrolytes – this means that they will conduct electricity very well ex – sulfuric acid, hydrochloric acidweak acids dissolved in water do not produce a lot of hydrogen ions and are not good electrolytes ex - acetic acid (vinegar)
5 Properties of Bases Bitter taste Slippery – ex soap Affect indicator colorsred litmus paper turns bluephenolphthalein turns bright pinkEmulsify (dissolve) fats and oilsThis is why we use bases as soap, they dissolve dirt and oils that are on our body)This is why cleaners often contain ammonia, the cleaner will “cut” through grease and we can wipe it away.
6 Properties of Bases Usually contain OH- ion Why are bases called proton acceptors?their OH- ions combine with H+ ions (protons from acids) to form waterCommon basessodium hydroxide (NaOH)potassium hydroxide (KOH)AmmoniaLyeSoapMilk of magnesia
8 The pH ScaleThe name, pH, has been reported to come from a variety of places including: pondus hydrogenii (Latin), pouvoir hydrogène (French) and potential of hydrogen (English).However pH is actually a shorthand for its mathematical definition, in chemistry a small p is used in place of writing − log10 and the H should more correctly be [H+], standing for concentration of hydrogen ionsSimply put - the pH of a solution is a measure of the amount of its H+ ion.Remember that the H+ ion is what is formed when an acid is dissolved into water.
9 The pH ScaleSO, the pH of a solution is actually a measure of how acidic it is.But, the scale is a reverse scale, so the lower the number, the higher the acidity.
10 The pH Scale the range is from 0 to 14 What is a solution like if... its pH is below 7?its pH is 7?its pH is above 7?acidicneutralbasic
11 When Acids & Bases Combine… Formation of SaltsWhen acids react chemically with bases, they neutralize each other AND form a type of compound called salts.water – the compound formed from the positive H ion of an acid and the negative OH ion of a basesalt – the compound formed from the negative ion of an acid and the positive ion of a base.neutralization - acid and base react to form a salt & water. It is a type of double replacement reaction.Oxi #’sHCl + NaOH NaCl + H2O“Hydrochloric Acid plus Sodium Hydroxide yields Sodium Chloride and Water”
12 When Acids & Bases Combine… How to Calculate a Neutralization Reactionthe acid’s H’s and the base’s OH’s must be the same #use coefficients if you need toThese will combine to form the water (H2O)put together the leftover parts to make the salt (base part 1st)don’t multiply subscripts, instead wrap the part in parentheses and put the needed subscript outsideEx #1: HCl + KOH1 H and 1 OH cancelthis leaves a Cl and a Kthus, the salt produced is KCl
13 What salt is made from each of the following neutralizations? Ex #2: H2SO4 + NaOH2 H’s but only 1 OH, so you have to put a 2 in front of the the NaOH so that you have enough OH’s to “hook up” with the H’s to make water (H2O)this leaves SO4 and 2 Nathus, the salt produced is Na2SO4(base part first, acid part second)What salt is made from each of the following neutralizations?HNO3 and NaOHLiOH and HBrH2SO4 and KOHHCl and Al(OH)3
14 Neutralize these or I’ll whine. Complete the following neutralization reactions.Circle the acid, Square the base, & Triangle the salt.LiOH + HBr -->HCl + FrOH -->H2SO4 + KOH -->Ca(OH)2 + HF -->H2SO4 + Al(OH)3 -->
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