Acids, Bases and Salts

Introduction Acids tend to have a _ _ _ _ taste (vinegar for e.g contains _ _ _ _ _ _ _ _ acid and _ _ _ _ _ juice contains citric acid) Many Alkalis have a soapy/slippery feel. When alkalis do NOT dissolve in water they are called _ _ _ _ _.

How strong??? Acids have a pH _ _ _ _ than 7. The _ _ _ _ _ _ _ _ the acid the _ _ _ _ _ the pH number. _ _ _ _ _ _ _ _ solutions have a pH of more than 7. The stronger the alkaline the _ _ _ _ _ _ the pH number. pH scale

Acids An acid is a compound containing hydrogen which become H+ _ _ _ _ in _ _ _ _ _. Acids turn _ _ _ _ litmus paper _ _ _. They turn universal indicator _ _ _ if they are strong, and orange and yellow if they are _ _ _ _. Properties of Acids: Sour taste, Affect indicators, Neutralize hydroxides, React with metals-releasing hydrogen React with metal oxides, React with carbonates

Used in __________ (clue: plants) and explosives Examples of acids NAME FORMULA pH FOUND IN Sulphuric acid H2SO4 1 ____ ___________ _ _ _ _ _ _ acid C6H8O7 Weak acid Lemons, oranges Ethanoic acid _______ 4 Vinegar _ _ _ _ _ _ acid HNO3 Used in __________ (clue: plants) and explosives Carbonic acid H2CO3 _________ Hydrochloric acid ___ Stomach

Alkalis Alkalis turn _ _ _ litmus paper _ _ _ _. They turn _ _ _ _ _ _ _ _ _ indicator dark blue or purple if they are _ _ _ _ _. Alkalis are a type of BASE: ones that _ _ _ _ _ _ _ _ in water. They _ _ _ _ _ _ _ _ _ _ acids. They release ___- ions in water BASES Neutralize acids, forming water as one product. React with nonmetal oxides. All metallic hydroxides (except those of active metals) are pretty much insoluble in water. They are weakly acidic in the presence of strong bases. That is, they are amphoteric, which means that they may act like an acid or a base.

Examples of Bases and Alkalis NAME FORMULA DISSOLVE IN H2O? ALKALI OR BASE? FOUND IN __________________ CuO No _______ - Sodium hydroxide _____ Alkali Used to remove grease from ovens + used to make _ _ _ _ ___________ NH3 Yes ________ Main active ingredient in household _ _ _ _ _ _ _ _ fluids __________ Ca(OH)2 ___ Base Slaked lime used in agriculture Aluminium hydroxide Al(OH)3 ____ Used in some _____________ tablets

Neutral substances _ _ _ _ _ is a neutral substance It turns universal indicator paper green No effect on _ _ _ _ _ _ paper It has a pH of exactly __

Neutralisation H2O(l) The making of _ _ _ _ _! + This reaction is called neutralisation. The alkali has neutralised the _ _ _ _ by removing its H+ ions, and turning them into _ _ _ _ _. H2O(l) http://www.bbc.co.uk/schools/gcsebitesize/chemistry/chemicalreactions/0acidsbasesrev5.shtml

Uses of Neutralization: Indigestion tablets: weak _ _ _ _ in these will react with ___________ acid in your stomach….so go easy on the Steers!! Soil treatment-farming: _ _ _ _ _ _ soil is treated with a BASE…why not alkali? One other use: waste from factories: waste from many factories are often acidic. If this acidic solution is not treated and enters rivers it can kill fish. Slaked lime (calcium hydroxide) is often used to neutralise the acid. Insect stings: - _ _ _ stings are acidic…so can be treated with a base (calamine lotion-zinc carbonate). Wasp stings are _ _ _ _ _ _ _ _ hence an acid (vinegar-ethanoic acid) can be used.

Different methods of salt production Acid + metal _ _ _ _ _ Method 2 : Acid + metal carbonate Method 3: Acid + _ _ _ _ _ _ Salt + water Salt + water + ____ SALTS Compound formed of positive ions of aqueous bases and negative ions of aqueous acids. The solubility of salts in water varies. Salt-Producing Reactions: Metal reacting with an acid, Reaction of nonmetallic oxide with aqueous acid, Reaction of nonmetallic oxide with aqueous base, Acid-base neutralization, Ionic reaction, Reaction of acid with a carbonate, Reaction of a metallic oxide with a nonmetallic oxide. Salt + water

What you need to remember!! Properties and examples of acids (weak and strong) Properties and examples of alkalis and bases (weak and strong) Preparation, separation and purification of of neutral substances (soluble salts and insoluble salts) pH scale and other indicators Reactions of making of salts

Thankyou for listening!! Good luck for the test.