Acid Base Reactions

An acid can react with bases, alkalis and carbonates to form a salt and water. Carbon dioxide is produced when carbonates are used The process is referred to as neutralisation eg HCl + NaOH -----> NaCl + H[sub]2[/sub]O 2HCl + Na[sub]2[/sub]CO[sub]3[/sub] ------> 2NaCl + H[sub]2[/sub]O + CO[sub]2[/sub] [b]The Basics of Acid Base Reactions[/b] [li] Determine the concentration of an unknown acid - by measuring the amount of acid required to neutralise a fixed volume of a known concentration of base[/li] [li]Determine the concentration of an unknown base - by titrating it against a fixed volume of known concentration of acid [/li] [b]Acid Base Titrations[/b] Acid-Base Titrations fall into 4 categories 1. strong acid - strong base 2. strong acid - weak base 3. strong base- weak acid 4. weak acid - weak base When a weak or strong acid is being analysed it is usual to use a strong base as standard solution to titrate against [li]Similarly when a weak or strong base is being analysed it is usual to use a strong acid as standard solution to titrate against[/li] [li]Never use weak acid with weak base.[/li] [b]The PH At The Endpoint Of Titration [/b] [table id="xchangetbl" ][thead][tr] [th] Acid[/th] [th]Base [/th] [th]PH at Endpoint [/th] [/tr][/thead][tbody] [tr][td]Strong[/td][td]Strong[/td][td]7[/td][/tr] [tr id="alt"][td]Strong[/td][td]Weak[/td][td]<7[/td][/tr] [tr][td]Weak[/td][td]Strong[/td][td]>7[/td][/tr] [tr id="alt"][td]Weak[/td][td]Weak[/td][td]~7[/td][/tr] [/tbody][/table] Introduction To Volumetric Analysis <--[a href="?id=1011-160-1&t=Volumetric-Analysis-|-An-Introduction"]Prev[/a] Next---> Contributed by Nuruddin Boateng- MBCS,MNZCS,MSc IT,BSc(Hons)Chemistry, Dip Ed.