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
DEFINITION OF CATALYST?
SUBSTANCE THAT INCREASES THE RATE OF REACTION WITHOUT IT BEING USED UP
DEFINITION OF ACTIVATION ENERGY?
THE MINIMUM AMOUNT OF ENERGY NEEDED BETWEEN COLLIDING PARTICLES IN ORDER FOR A SUCCESSFUL COLLISION TO TAKE PLACE
USES OF TRANSITION METALS AND THEIR COMPOUNDS?
-OFTEN USED AS CATALYSTS AND COME VERY HANDY TO INDUSTRIES
-THIS IS BECAUSE THEY REDUCE THE AMOUNT OF ENERGY NEEDED IN INDUSTRY, WHICH THEN REDUCES THE COSTS
-THEY HAVE DIFFERENT OXIDATION STATES, WHICH HELPS THEM IN THE TRANSFERRING OF ELECTRONS
-THEY OFFER ALTERNATIVE REACTION PATHWAYS WITH LOWER ACTIVATION ENERGY
WHAT IS THE HABER PROCESS AND WHY IS IT IMPROTANT?
ITS THE PROCESS OF MAKING AMMONIA, WHICH IS IMPORTANT BECAUSE IT IS USED TO MAKE FERTILISERS, WHICH INCREASE CROP YIELD
WHAT TAKES PLACE IN THE HABER PROCESS (N2+3H2 ⇌ 2NH3)?
-THE REACTANTS ADSORBS TO THE CATALYST SURFACE
-THIS WEAKENS THEIRS BONDS
-FINALLY, THIS ALLOWS THE REACTION TO PROCEED AT A LOWER ACTIVATION ENERGY
WHAT DOES A CATALYTIC CONVERTER CONTAIN AND WHAT DOES IT DO?
-CONTAINS PRECIOUS METALS
-IT COVERTS POLLUTING GASSES INTO NON POLLUTING GASSES FROM INTERNAL COMBUSTION ENGINES
EXAMPLE OF CATALYTIC CONVERTER?
CONVERTS CARBON MONOXIDE AND NITROGEN MONOXIDE TO CARBON DIOXIDE AND NITROGEN
HOW IS ALUMINA EXTRACTED FROM BAUXITE?
-THE LARGE PIECES OF BAUXITE ARE FIRST CRUSHED UP INTO SMALL GRAINS
-THEN HOT SODIUM HYDROXIDE IS ADDED, WHERE THE ALUMINUM COMPOUNDS START TO DISSOLVE AND A SLURRY IS FORMED
-THE SLURRY IS THEN FILTERED TO REMOVE RESIDUE AND LEAVE BEHIND A SOLUTION CONTAINING ALUMINUM ALUMINUM COMPOUNDS
-NEXT THE SOLUTION IS ALLOWED TO COOL SO THAT IT CRYSTALLIZES. FLOCCULANTS ARE ADDED TO AID THIS SEDIMENTATION PROCESS. THE SODIUM HYDROXIDE WILL BE ABLE TO BE RE USED AS IT WILL BE RECOVERED IN THIS PROCESS.
-LASTLY THE ALUMINUM HYDROXIDE CRYSTALS ARE HEATED TO PRODUCE ALUMINA. THIS STEP IS CALLED CALCINATION BECAUSE WATER IS BEING REMOVED.
HOW IS ALUMINUM MADE FROM ALUMINA?
-ALUMINA IS DISSOLVED IN CRYOLITE
-ELECTROLYSIS IS USED
WHY IS AQEOUS ALUMINA NOT USED IN THE PROCESS OF IT TURNING INTO ALUMINUM?
AS AL IS HIGHER THAN H IN THE ELECTROCHEMICHAL SERIES
-SO H2 WOULD BE PRODUCED AND NOT AL
WHY IS ALUMINA DISSOLVED IN CRYOLITE?
-ALUMINA MELTS AT OVER 2000 DEGREES AND CRYOLITE IS MUCH LOWER
-MEANING IT WOULD BE WAY MORE COST EFFIECIENT
WHAT ELSE LOWERS THE MELTING POINT OF ALUMINA SO IT IS MORE COST EFFECTIVE WHEN ELECTROLYSIS TAKES PLACE?
ADDING ALUMINUM FLOURIDE
WHAT HAPPENS AT THE ANODE WHEN ALUMINUM IS MADE FROM ALUMINA?
-OXYGEN IS FORMED AT THE ANODE
-REACTS WITH THE GRAPHITE ANODE TO PRODUCE CO2
-HYDROGEN FLOURIDE IS ALSO FORMED (FROM THE CRYOLITE)
WHAT HAPPENS AT THE CATHODE WHEN ALUMINUM IS MADE FROM ALUMINA?
-AL3+ IONS ARE PRESENT WHICH THEN GAIN 3 ELECTRONS AND MAKE THEM INTO ALUMINUM
-THE ALUMINUM PRODUCED IS MOLTEN AS IT IS UNDER SUCH A HIGH TEMPERATURE
KEY POINTS OF EXTRACTING TITANIUM FROM ITS ORE
-TITANIUM ORE OTHERWISE KNOWN AS RUTILE, CONTAINS TITANIUM OXIDE TiO2
-MAGNESIUM IS USED AS THE REDUCING AGENT
-THIS PROCESS TAKES PLACE OVER 2 STEPS MAKING IT A BATCH PROCESS
-THIS MEANS ONLY SMALL AMOUNTS OF TITANIUM CAN BE MADE AT A TIME
WHY IS TITANIUM EXPENSIVE TO PRODUCE?
AS IT TAKES 2 STEPS TO MAKE THE TITANIUM AND IT IS MADE IN SMALL AMOUNTS.
WHAT ARE THE 2 STEPS INVOLVED IN CARRYING OUT EXTRACTION OF TITANIUM FROM ITS ORE?
1) TITANIUM OXIDE IS CONVERTED TO TITANIUM CHLORE BY USING CHLORINE AND CARBON
2)TITANIUM CHLORIDE PRODUCED IN STEP 1 IS REDUCED BY MAGNESIUM
WHAT TYPE OF ENVIRONEMT IS STAGE 2 OF EXTRACTING TITANIUM FRO ITS ORE TAKEN PLACE IN?
-REACTION IS CARRIED OUT IN AN ARGON ATMOSPHERE
-THIS PREVENTS TITANIUM FORMED FROM REACTING WITH WATER OR OXYGEN
