C2 Flashcards
What is the chemical name and symbol for salt?
- Sodium Chloride
* NaCl
Where is salt extracted from?
Large underground deposits left from millions of years ago, where seas once evaporated.
What is rock salt a mixture of?
Rock salt contains sodium chloride and other impurities.
How is rock salt brought to the ground?
Hot water is pumped underground which causes the salt to dissolve in the water. The water is the pushed to the surface under the pressure of water. This is called solution mining.
What must be done after salt is extracted from an area?
Any holes left in the ground must be properly filled in to prevent the land from subsiding and collapsing into the holes.
What is the earth made of?
Crust, lithosphere, mantle and core.
What is the crust made of?
Solid rock.
What does the lithosphere include?
The crust and upper part of the mantle, made up of a jigsaw structure.
What happens as you go deeper into the mantle?
The temperature increases.
What is a use for rock salt in its raw state?
It can be used as road salt.
What products are made during the electrolysis of brine?
- Hydrogen
- Chlorine
- Sodium Hydroxide
What is the chemical name for brine?
Sodium Chloride Solution.
What type of material are the electrodes made out off?
The electrodes are made of an inert material. Meaning it does not react with with the products or reactants.
At what electrode is hydrogen produced?
Hydrogen is made at the cathode.
At what electrode is chlorine gas produced?
Chlorine gas is produced at the anode.
How is sodium hydroxide formed during electrolysis?
Sodium hydroxide is made from the left over ions.
What does radioactive decay create a lot of inside the earth?
Heat.
What do tectonic plates do?
They float on the mantle.
How fast do the plates move?
About 2.5cm per year.
What can tell us what’s below the crust?
The seismic waves.
Why do scientists use seismic waves?
To study the earth’s structure.
what industry carries out the electrolysis of brine?
The Chlor-alkali industry.
Who created the theory about the plates moving?
Alfred Wegener in 1914.
Why was Wegener’s theory not accepted?
There was no real convincing evidence.
What is the name of the ridge that runs the whole length of the Atlantic?
The Mid-Atlantic ridge.
What was the evidence that suggested the sea floor was spreading and confirmed Wegener’s theory?
Magma rises up through the sea floor, solidifies and forms underwater mountains that are roughly symmetrical.
How are volcanoes formed?
Volcanoes are formed when magma from the mantle emerges through the Earth’s crust.
When is molten rock called magma and when is it called lava?
It is magma when it is below the surface of the earth and lava when it erupts from the volcano.
What else can cause volcanoes?
The oceanic and continental crust colliding.
How does the oceanic and continental crust colliding cause volcanoes?
- The crust at the ocean floor is denser than the crust below the continents.
- When they collide, the dense oceanic plate will be forced under, called subduction.
- As the oceanic crust is forced down, it melts and starts to rise. If the molten rock finds a way to the surface , volcanoes form.
How is igneous rock made?
Made when any sort of molten rock cools down and solidifies. The type depends on how quickly the molten rock has cooled.
How do scientists try to predict volcanic eruptions?
They study things like magma movement below or near to the volcano.
What are the three steps in the forming of sedimentary rock?
- Layers of sediment laid down in lakes or seas.
- Pressure squeezing out the water.
- Fluids flow through the pores and deposit natural mineral cement.
What is limestone made of?
Calcium carbonate.
What is the word and symbol equation for the thermal decomposition of limestone into carbon dioxide and calcium oxide?
calcium carbonate –> calcium oxide + carbon dioxide
CaCO3 –> CaO + CO2
How are metamorphic rocks formed?
Metamorphic rocks are formed by the action of heat and pressure on sedimentary (or even igneous) rocks over long periods of time.
What do igneous rocks contain?
Different minerals in randomly arranged interlocking crystals.
What are ores?
Ores are minerals that can contain useful materials. For example aluminium and iron are extracted from their ores and are used in construction.
How is glass made?
Glass is made by melting limestone (calcium carbonate), sand (silicon dioxide) and soda (sodium carbonate).