Acids GapFill

Acids can react with metals to form  a metal oxidea halogenan alkalia salta metal acida metal carbonate and hydrogen, with metal hydroxides and metal oxides to form a salt and  watera basea hydrocarbonhydrogen carbonatemethaneoxygen, and with metal carbonates to form a salt, water and  hydrogen carbonatehydrogencarbon monoxidecarbon dioxidecarbona metal. The salts which are formed in these reactions depend on the metal and the acid used.

To make a pure, dry sample of a soluble salt, heat  an alkanea halogenwatera salt solutionan acidan alcohol and then add a solid, insoluble metal, alkali or base until no more reacts. The mixture should be filtered and the solution heated to  meltabsorbfreezeevaporatecondensedissolve the water away until  transparentbluecolourlesspurewhitesoft, dry salt crystals appear.

Acids release  H⁺Ca²⁺Cl⁻Na⁺N⁺K⁺ ions in solution, and alkali solutions contain OH⁻ ions. The  densitywaterpHcolouracidosisweighing scale uses the numbers 0 to 14 to describe the acidity or  concentrationionisationalkalinityreactivitysolubilitydensity of a solution, which can be determined using  an electrodea cathodeuniversal indicatora thermometera barometera buffer.

In a titration, acid is placed in a  pipettebeakerburetteconical flaskcondensermeasuring cylinder and dripped slowly into a beaker containing a  metal carbonatesolidgasmetal oxidebasemetal and a suitable indicator, which changes colour when the reaction is complete. Strong acids completely  precipitatecoolreactionisedeioniseevaporate in solution, compared to weak acids, which do not.

When a gas is produced in a reaction, there are many tests which can be used to find out what the gas is. For example:

• a lit splint gives a squeaky pop with hydrogen
• carbon dioxide turns  metalslime waterthe airwatermirrorsacids cloudy