CHEMISTRY Flashcards
WHAT IS AN ACID?
A SUBSTANCE THAT DISSOCIATES IN WATER TO FORM H+ IONS
WHAT IS A BASE?
A SUBSTANCE THAT REACTS WITH ACIDS TO FORM SALT AND WATER
WHAT IS AN ALKALI?
A BASE THAT DISSOLVES IN WATER TO FORM OH- IONS
WHAT DOES AMPHOTERIC MEAN?
SUBSTANCE THAT CAN ACT AS BOTH AN ACID AND A BASE
WHAT IS THE CHEMICAL FORMULA FOR ALUMINUM OXIDE (ALUMINA)
Al₂O₃
PROPERTIES OF ALUMINA?
-CHEMICALLY INERT MEANING IT IS UNREACTIVE UNLESS IN CERTAIN CONDITIONS SUCH AS A HOT ACID OR BASE
-AMPHOTERIC, AS IT REACTS WITH ACIDS OR BASES
CHEMICHAL EQUATION OF ALUMINA REACTING WITH AN ACID:
Al2O3 + 6HCl →2AlCl3 + 3H2O
USES OF ALUMINUM OXIDE (ALUMINA):
-VERY UNREACTIVE, SO IT IS GOOD FOR PAINTS, SUNSCREENS AND GLASS
-IT’S ALSO USED IN CHROMATOGRAPHY AS A STATIONARY PHASE
-ALSO AN EFFECTIVE DESICCANT (DRYING AGENT)
WHAT IS THE DEFINITION OF SALTS?
SALT IS FORMED WHEN THE H+ IN ACIDS IS REPLACED BY ANOTHER POSITIVE ION (USUALLY METAL OR AMMONIUM)
WHAT SALT DOES NITRIC ACID, HNO₃ FORM?
NITRATE, NO3-
WHAT SALT DOES HYDROCHLORIC ACID, HCl FORM?
CHLORIDE, Cl-
WHAT DOES SULFURIC ACID, H₂SO₄ FORM?
SULFATE, SO₄²-
WHAT ARE METAL OXIDES?
METAL OXIDES ARE BASES (REACTS WITH ACIDS TO FORM SALT AND WATER)
METAL OXIDE + ACID → SALT + WATER
WHAT ARE METAL HYDROXIDES?
METAL HYDROXIDES ON THE OTHER HAND ARE ALKALIS (A BASE THAT DISSOLVES IN WATER TO FORM OH- IONS)
WHAT IS ELECTROLYSIS?
THE DECOMPOSITION OF A COMPOUND USING ELECTRICITY
WHAT DOES THE TERM MOLTEN MEAN?
SUBSTANCE IS IN LIQUID STATE
WHAT IS A CATION?
POSITIVE ION
WHAT IS AN ANION?
NEGATIVE ION
WHAT DOES THE TERM AQUEOUS MEAN?
DISSOLVED IN WATER
PANCAKE DEFINITION
-Positive Anode
-Negative Cathode
IONIC SUBSTANCES PROPERTIES:
-GIANT IONIC LATTICE
-THESE CONSIST OF MANY STRONG ELECTROSTATIC BONDS BETWEEN OPPOSITELY CHARGED IONS, THEREFORE THEY HAVE HIGH MELTING POINTS
- THEY DO NOT CONDUCT WHEN SOLID BECAUSE IONS CAN’T MOVE
-HOWEVER THEY CAN CONDUCT WHEN MOLTEN OR DISSOLVED AS IONS CAN MOVE
WHAT DOES THE TERM EFFLUENT MEAN?
-THE LIQUID WASTE THATS DISCHARGED TO RIVERS OR STREAMS BY FACTORIES
WHAT CAN LEAD THE EFFLUENT TO BE ACIDIC AND HOW CAN YOU STOP THIS?
-INDUSTRIES/FACTORIES USE SULFURIC ACID, THIS RESULTS IN THEIR WASTE BEING ACIDIC.
-TO STOP THIS YOU HAVE TO INCREASE THE PH OF THE EFFLUENT TO MAKE IT NO LONGER ACIDIC
WHAT IS MEANT BY REFRACTORY MATERIALS? WHAT IS A GOOD EXAMPLE?
-A MATERIAL THAT IS PHYSICALLY AND CHEMICALLY STABLE AT HIGH TEMPERATURES
-ALUMINA IS A REFRACTORY MATERIAL AS IT MATCHES THE DESCRIPTION OF IT BEING CHEMICALLY AND PHYSICALLY STABLE AT HIGH TEMPERATURES
-THIS MAKES IT AN EXCELLENT MATERIAL FOR FURNACES AND REACTORS