Gases in the Atomosphere Flashcards
What is the percentage of oxygen in the atmosphere
21%
what is the percentage of nitrogen in the atmosphere
78%
what is the percentage of argon in the atmosphere
0.9%
what is the percentage of C02 in the atmosphere
0.04%
what is the scientific word for burning
Combustion:
when magnesium is burned, what colour flame and what product is produced, and what happens when that product is dissolved in water
Magnesium - white flame, white powdery ash - magnesium oxide
Magnesium oxide is not very soluble –> a little bit may dissolve to form magnesium hydroxide
when sulfur is burned, what colour flame and what product is produced, and what happens when that product is dissolved in water
Sulfur - burns with a blue flame, sulfur dioxide (=sulfur (IV) oxide)
Sulfur dioxide = colourless and poisonous
dissolves in water to become sulfurous acid - H2SO3
what is the difference betwen sulfurous acid and sulfuric acid
sulfurous is H2S03 and sulfric is H2S04
when hydrogen is burned, what colour flame and what product is produced
Hydrogen - pale blue flame. produces water. Hydrogen is very very very combustible - when reacting with oxygen it results in an explosion
what do metal oxides react with and what do they form
Metal oxidise react with acids to form salts + water
are metal oxides soluble in water and if they are what are the produces
Most metal oxides are not soluble in water. The few that ARE soluble react with water to form alkaline solution with hydroxide ions, metal hydroxide
what do nonmetal oxides react with and what do they form
Non-metal oxides react with alkalis/bases (this is because they are acidic oxides) to form salts
are nonmetal oxides soluble in water and if they are what are the produces
Non-metal oxides are quite soluble in water
Non-metal oxides form acidic solutions containing H+ ions
what is the general equation of metal carbonate + acid
metal carbonate +acid –> salt + co2 + water
what is thermal decomposition
Thermal decomposition = when heat is used for the breakdown of something
what is another name for calcium carbonate
Calcium carbonate = limestone + marble
what happens to most metal carbonates when they undergo thermal decompostition
When most carbonates undergo thermal decomposition this forms metal oxide and CO2
what are the 3 greenhouse gases
The three greenhouse gases:
carbon dioxide
methane - CH4
water vapour
what are the 3 fossil fuels
The three fossil fuels are:
Coal
Oil
Gas
how do we get petrol
We get petrol from the fractional distillation of crude oil
what do greenhouse gases do
Greenhouse gases ‘trap the radiation from the Sun’, but absorbing the radiation. These gases absorb the radiation and then emit it in all directions.
what is the greenhouse effect (2)
The Greenhouse Effect: the process of the Earth warming up/being warm due to these gases in the atmosphere absorbing and emitting radiation.
The greenhouse gases are able to absorb radiation due to being polar molecules.
what is polarity
A molecule is polar when one side is slightly more negative and the other is slightly more positive.
how does polarity happen
Polarity comes about because the different atoms in the molecule attract the shared electrons to different amounts - so if one attracted it more, it becomes slightly electronegative, and so the other side of the molecule would become slightly positive.
what can cause polarity
Water = polar molecule
Carbon dioxide is not naturally polar as it is a linear shape (the atoms are in a straight line)
HOWEVER, when the CO2 molecule starts to vibrate, it becomes polar, allowing it to be a greenhouse gas.
if a molecule is linear then the atoms cannot shift causes the electrons to be more on one side
Why are N2, and O2 not greenhouse gases:
N2 and O2 are molecules that are made up of the same type of atoms (same elements) bonded together. This means there is no difference in how strongly they attract the electrons, so the electrons are not pulled closer to either side, so both remain uncharged and so not polar.
