Chemistry Flashcards
What are the signs that a chemical reaction is happening,name as many as possible?
1)A colour change
2)Explosions
3)Bubbling/fuzzing
4)Noises e.g. “bang” or “pop”
4)Smoke
5)Mediums changing states of matter
6)Different smells
7)Flames
8)a colour change
What is the definition of a chemical reaction?
When a substance or substances you start with are turned into something new.
What is a reversible chemical reaction?
A chemical reaction that can go in both directions,with reactants turning into products and products turning back into reactants.
What is a catalyst?
A substance that speeds up a chemical reaction without being consumed or chemically changed.
What are the properties of a solid?
Fixed shape
Fixed volume
High density
Cannot be compressed
What are the properties of a liquid?
No fixed shape
Fixed volume
Lower density
Nearly incompressible
What are the properties of a gas?
No fixed shape
No fixed volume
Low density
Can be easily compressed
What does the conservation of mass mean?
The mass of the reactant is the same as the mass of the products.
What is the complete combustion equation?
Fuel+Oxygen➡️Carbon Dioxide+Water
How can you test for carbon dioxide in combustion?
Lime water would go cloudy
How can you test for water vapour in combustion?
Litmus paper would go white
Explain and give an example of an endothermic reaction.
An endothermic reaction is when heat is absorbed into atoms, which cause the surroundings to get colder.An example is when you’re holding an ice pack in your hand and heat energy from your hand is absorbed into the ice pack causing the ice pack to get warmer and your hand to be colder.
Explain and give an example of an exothermic reaction.
An exothermic reaction is when heat is released which causes the surroundings to get hotter.An example of this is when a volcano explodes and the heat energy from the explosion makes the surrounding hotel meaning that if you were there when the volcano exploded you would start to get hotter.
What is it called when two liquids react together and a solid product os formed?
Precipitation reaction
Explain in detail what thermal decomposition is.Give an example to help.
Thermal decomposition is when something is heated, and because of this, it breaks down.An example of this is when copper carbonate is heated and it breaks down into copper oxide and copper dioxide.
What is an element,compound and mixture?
Element=made of the same type of atom
Compound=made of two or lore elements chemically joined together
Mixture=made of two or more elements that aren’t chemically joined together
What is the incomplete combustion equation?
Fuel+Oxygen ➡️Carrbon Monoxide+Carbon+Water
Why does incomplete combustion?Which product of the reaction is toxi and why?
It occurs because of a lack of oxygen, and carbon monoxide is created.It’s toxic because it damages the red blood cells in your body making it harder for blood to be transported around the body and you will never know ots there because it’s odourless and colourless.That’s why some people have carbon monoxide alarms in there houses.
As well as heat, what other energy can be released in an exothermic reaction?
Light, sound, electricity
What is the definition of a fuel?
A material that can be burt to produce heat energy.
What has happened if the mass has decreased in a chemical reaction?
A gas has escaped.
What has happened if the mass increased?
The gas has combined with the reactant.
