Test Flashcards
(35 cards)
What is the chemical reaction?
A chemical reaction takes place when two or more substances combine to make one or more new substances
What is a physical change?
A physical change is where are known as substances are made, but there is a change an appearance of a chemical physical changes are not chemical reactions. Examples of physical changes include state changes like changing from a solid to liquid and dissolving physical changes are usually reversible.
What are everyday chemical reactions?
Some Aphrodite chemical reactions are cooking rock fuel, burning and digestion, but some not so useful. Chemical reactions is mould growing explosions if not planned and rusting.
What is a reactant?
And a chemical reaction the starting substances are called reactants
What are products?
Products are new substances formed from reactants
What is the chemical change word problem?
Reactants➡️ products
How can you identify if a chemical reaction has taken place?
There is a change of colour
Change of temperature
Bubbles of a gas are produced
A perseverate forms (a solid produced when two liquids react)
Light or sound is given out(other forms of energy)
What is an example of a chemical reaction?
One example is an iron nail and copper sulphate solution. The iron nail goes slightly red.
Another example is magnesium ribbon and hydrochloric acid the solution fizzled
What is a reaction rate?
A reaction rate is how quickly a reaction happens
What is a collision?
Chemical reactions only happen when reactants are in contact with each other the reactant particles need to bump into each other for a reaction to a car when the reactant particles do this we call it a collision
The more collisions there are between reactants the what happens to the reaction rate
Faster
What are some examples of a reaction which scientist tried to
Cooking and manufacturing fertiliser
Give an example of reaction rate which scientist try to slow down
Spoiling and rusting
How does a higher temperature affect the reaction rate?
A higher temperature equals fast moving particles and more collections
How does a lower temperature affect a reaction rate?
A lower temperature equals slow moving particles in less collisions
How does particle size affect the speed of a chemical reaction?
By reducing up the particle size we can increase the surface area of the reactant and this increased the reaction rate this is because the larger the surface area the more collisions that can happen between the reactions to which means the reaction will go faster
What will the reaction do if it has a high surface area?
It will have more collisions, which means I’ll go faster
What will the reaction do if it has a low surface area?
If the reaction has a low surface area that means less collisions in slow reaction rate
What is concentration?
Concentration as a measure of how many particles are in certain volume/space. More concentrated solutions have more particles press in the same volume of less concentrated solutions.
How many particles do high concentrations in low concentration
High concentrations have many particles will low concentrations have little particles
What does increasing the concentration due to an experiment
Increasing a concentration increases the rate of reaction. The higher concentration the faster the reaction rate.
What is a catalyst?
A task is a substance which increases the reaction rate of a chemical reaction that is not used up in the reaction
What is an example of a catalyst?
Maganese dioxide powder
What are the four ways which we can change the reaction rate of a chemical reaction?
Change temperature
Change in concentration
Change a particle size
Add a catalyst
