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21 Cards in this Set
- Front
- Back
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WHAT IS ATMOSPHERE?
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THE MIXTURE OF GASES THAT SURROUNDS
THE EARTH.IT GOES THINNER AS YOU GO FURTHER FROM THE EARTH'S SURFACE. IT IS DIFFICULT TO SAY EXACTLY WHERE THE ATMOSPHERE STOPS. |
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WHAT IS AIR?
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MIXTURE OF GASES IN THE LOWER PART
OF THE ATMOSPHERE. ABOUT 99% OF THE AIR IS MADE UP OF JUST 2 GASES, NITROGEN AND OXYGEN. |
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WHAT IS THE COMPOSITION OF AIR?
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NITROGEN (N2) - 78%, OXYGEN (O2)- 21%,
ARGON (Ar) - 0.9%, CARBON DIOXIDE (CO2) - 0.04%, WATER AND OTHER GASES - TRACES. AMOUNT WATER VAPOUR IN THE AIR CHANGES, BUT COMPOSITION OF DRY AIR STAYS CONSTANT. |
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WHAT ARE THE MAIN SOURCES OF
AIR POLLUTION? |
THE MAIN SOURCES OF POLLUTION ARE
THE BURNING OF FOSSIL FUELS AND THE RELEASE OF MAN-MADE CHEMICALS INTO THE ATMOSPHERE |
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HOW CAN WE FIND THE AMOUNT OF
OXYGEN IN THE AIR? |
It is measured by using 2 syringes connected with silica tube containing copper. The volume
of air in the syringes is measured at the start. Then the copper is heated strongly while the air is passing slowly from one syringe to another. It continues until there is no further change in the volume of gas. At the end it is measured again. |
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WHAT ARE THE RESULTS OF THE METHOD
USED TO MEASURE THE AMOUNT OF OXYGEN IN THE AIR? |
VOLUME OF THE AIR AT THE START WAS
100 CM3. VOLUME AT THE END WAS 79 CM3. 100 - 79 = 21 CM3. (21% OF OXYGEN) THE CHANGE IN VOLUME IS DUE TO LOSS OF OXYGEN WHICH REACTS WITH COPPER TO FORM COPPER OXIDE. |
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HOW CAN THE GASES IN THE AIR BE
SEPARATED? |
THEY CAN BE SEPARATED BY FRACTIONAL DISTILLATION OF LIQUID AIR. THE AIR IS
FIRST COOLED AND COMPRESSED TO TURN INTO A LIQUID. THE GASES CAN BE SEPARATED BECAUSE THEY HAVE DIFFERENT BOILING POINTS. |
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WHAT ARE THE PROPERTIES OF THE GASES
IN THE AIR? |
ALL THE GASES IN THE AIR ARE COLORLESS
AND HAVE NO SMELL, BUT THEY DIFFER IN OTHER PROPERTIES AND USES. |
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WHAT ARE THE PROPERTIES AND USES
OF NITROGEN? |
NITROGEN - most abundant gas in air,
insoluble in water, doesn't react easily with other substances. It is used for packaging food. It can be made to react, and is used to make ammonia and nitric acid, both of which are used to make fertilizers. Plants & animals need N2-containing compounds to make proteins. |
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WHAT ARE THE PROPERTIES AND USES
OF OXYGEN? |
OXYGEN - soluble in water, reacts with many
other substances. It's essential to life on Earth and respiration. O2 cylinders are used in hospitals for patients with breathing problems Needed for combustion as substances burn better if more O2 present. Used with fuel gas acetylene to produce very high temp. flame in oxyacetylene burners. |
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WHAT ARE THE PROPERTIES AND USES
OF ARGON? |
ARGON IS INSOLUBLE IN WATER AND IS
EXTREMELY UNREACTIVE. ORDINARY LIGHT BULBS ARE FILLED WITH ARGON SO THAT THE FILAMENT DOE NOT BURN OUT. |
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WHAT ARE THE PROPERTIES AND USES
OF CARBON DIOXIDE? |
CARBON DIOXIDE - soluble in water but fairly
unreactive. Even though there are small amounts of it in the air, but it is very important to all living things. Green plants need it for photosynthesis. It is also used in some fire extinguishers and some fizzy drinks. |
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WHAT ARE THE TESTS FOR THE GASES
IN THE AIR? |
WHEN A GLOWING SPLINT IS PLACED IN
A TUBE WITH OXYGEN, IT RE-LIGHTS. CARBON DIOXIDE TURNS LIMEWATER IN A TUBE CLOUDY. THERE ARE NO SPECIFIC TESTS FOR NITROGEN AND ARGON. NITROGEN, CARBON DIOXIDE AND ARGON PUT OUT A BURNING SPLINT. |
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WHAT IS OXIDATION?
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IT IS A REACTION THAT TAKES PLACE WHEN
A SUBSTANCE REACTS WITH OXYGEN. WHEN SUBSTANCES REACT WITH OXYGEN, OXIDES ARE FORMED. |
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WHAT IS A COMBUSTION?
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IT IS A RAPID REACTION IN WHICH
A SUBSTANCE COMBINES WITH OXYGEN, CATCHES FIRE AND GIVES OUT ENERGY . |
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WHAT IS THE WORD EQUATION FOR
THE MAGNESIUM BURNED? |
MAGNESIUM + OXYGEN = MAGNESIUM OXYDE
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WHAT HAPPENS WHEN HYDROGEN SULPHIDE
IS BURNED? |
WHEN HYDROGEN SULPHIDE IS BURNED,
IT FORMS WATER (HYDROGEN OXIDE) AND SULPHUR DIOXIDE. hydrogen sulphide + oxygen ----------------
water + sulphur dioxide |
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WHAT IS A FIRE TRIANGLE?
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A FIRE NEEDS ALL 3 THINGS - A FUEL, OXYGEN
AND HEAT, FOR COMBUSTION. |
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WHAT NEEDS TO BE DONE TO PUT OUT A FIRE?
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TO PUT OUT A FIRE, YOU NEED TO REMOVE
ONE (OR MORE) OF THE 3 THINGS: FUEL, OXYGEN OR HEAT. |
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HOW DO FIRE EXTINGUISHERS WORK?
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MANY FIRE EXTINGUISHERS, INCLUDING
THOSE CONTAINING WATER AND CARBON DIOXIDE, WORK BY STOPPING OXYGEN GETTING TO THE FIRE AND COOLING IT DOWN |
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WHAT NEEDS TO BE DONE TO PUT OUT
A PERSON ON FIRE? |
A PERSON CAN BE WRAPPED IN A FIRE BLANKET OR SOMETHING LIKE A COAT, TOSTOP OXYGEN GETTING TO THE FIRE.
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