Topic 2 reactions Flashcards
What percentage of air is made up of oxygen
About 21%
Give 2 properties of oxygen
Colourless
Odourless
Name 2 uses of oxygen
Welding torches
Rocket fuel
Breathing apparatus in hospitals
A reaction that uses oxygen is know as what type of reaction
An oxidation reaction
Respiration uses oxygen and sugar and happens in our bodies - what is the equation
Sugar + oxygen —————> water + carbon dioxide + energy
Rusting is an example of what type of reaction
Oxidation
What is the word equation for rusting
Iron + oxygen + water —————> hydrated iron oxide
Burning a fuel requires oxygen. What is the word equation
Fuel + oxygen———> carbon dioxide + water + energy
What is another name for burning
Combustion
What is the test for carbon dioxide
Turns limewater milky
What is the test for water
Turns anhydrous copper sulfate from white to blue
Hydrogen peroxide can be broken down to two products - what are they?
Water and oxygen
What is added to speed up the break down of hydrogen peroxide
A catalyst (manganese dioxide)
What is the test for oxygen
Relights a glowing splint
What is a catalyst
A substance that speeds up a reaction but is not used up in the reaction
Give an example of a biological catalyst
Enzymes eg protease, amylase, lipase
Give 2 properties of hydrogen
Colourless
Odourless
Gas
Give 2 uses of hydrogen
Making margarine
As a clean fuel e.g some buses are hydrogen fuelled
As rocket fuel
What happens when magnesium is added to hydrochloric acid
It bubbles
Is exothermic reaction
Gives of hydrogen gas
How can you test for hydrogen
Add a lighted splint and it burns with a squeaky pop
What is the word equation for reaction between hydrochloric acid and magnesium
Magnesium + hydrochloric acid ————-> magnesium chloride + hydrogen
What gas is now used in air ships after the hindenburg disaster
Helium
Give 2 properties of carbon dioxide
Odourless
Colourless
Gas
Give 2 uses of carbon dioxide
Fizzy drinks
Fire extinguisher
Dry ice
Carbon dioxide can be made by adding calcium carbonate to hydrochloric acid. What is the word equation for this reaction
Calcium carbonate + hydrochloric acid ————-> calcium chloride + carbon dioxide + water
How do you test for carbon dioxide
Turns limewater milky
What is meant by an endothermic reaction
A reaction that takes in heat - the temperature will go down
What is meant by an exothermic reaction
Gives out heat - the temperature will increase
What is meant by thermal decomposition
Using heat to break down a substance
Copper carbonate can be broken down by thermal decomposition. What is the colour change that happens
From green to black
What is the black substance produced during the thermal decomposition of copper carbonated
Copper oxide
What gas is produced by thermal decomposition of copper carbonate
Carbon dioxide is produced
What is a reduction reaction
When oxygen is removed
What is a redox reaction
When one substance is oxidised and another substance in the reaction is reduced
In the redox reaction between sodium and magnesium oxide which substance is reduced?
Magnesium oxide has oxygen removed (reduced) to form magnesium
In the redox reaction between magnesium oxide and sodium what are the products and state which is oxidised and which is reduced
Magnesium oxide + Sodium ————> magnesium + sodium oxide
Magnesium oxide reduced
Sodium oxidised - oxygen added
What is meant by a reducing agent
The substance that reduces (removes the oxygen) from another substance e.g.sodium is reducing agent that removes the oxygen from magnesium oxide
What is the termite reaction
An exothermic reaction between iron oxide and aluminium
Example of a redox reaction
The iron oxide is reduced
The aluminium is oxidised
Write the word equation for the thermite reaction
Aluminium + iron oxide ——————> aluminium oxide + iron
