C1.3 Chemical Reactions Flashcards
What do chemical reactions do?
It tranfers energy to or from the surroundings. Also it makes new substances.
Are chemical reactions easily reversible?
No
How can you tell if a chemical reaction has taken place?
There could be a colour change, a noise, bubbles/fizzing, a change of temperature, a smell
How can you speed up a chemical reaction?
Increase the temperature of the reactants or use a catalyst
Is a catalyst used up in a chemical reaction?
No
A reversible change is often a?
Physical change
What do we call two or more elemetns chemically joined?
A compound
Does a compound have the same properties of the elements that make it up?
No
Which side does reactants go in a chemical equation?
Left
Which side does products go in a chemical equation?
Right
What does the arrow mean?
reacts to make
When magnesium and oxygen react it produces?
Magnesium Oxide
What is a fuel?
A material that burns to transfer energy by heating
State some examples of fuel
Petrol, diesel, coal, hydroge and cooking oil
What is combustion?
A chemical reaction that involves burning
What is oxidation?
A form of combustion where a reactant reacts with oxygen
State an example of oxidation
Rusting
What does non-renewable mean?
That the object is not replacable in our lifetimes
What does thermal decomposition mean?
Where a complex compound breaks down into simpler compounds and elements through heating
Name an example of thermal decomposition
Hydrogen Peroxide –> water + oxygen
In the thermal decomposition of carbonates, which gas is always given off?
Carbon Dioxide
How can you tell if carbon dioxide is a product?
Place it through lime water, if the lime water turns cloudy, carbon dioxide was present
What type of data is needed to draw a bar chart?
Discrete or categoric data
What does conservation of mass mean?
The total mass of reactants is the same as the total mass of products
If the mass of the products seems to have decreased - what must have happened?
At least one of the products was a gas - which escapes and lowers the mass of the remaining products
If the mass of the products seems to have increased - what must have happened?
At least one of the reactants was a gas - this then chemically joins another reactant to make the product heavier
How can you balance equations?
By writing numbers BEFORE the chemical symbols
What does a balanced equation mean?
Same number of each elements before and after the reaction
