What are the signs of a chemical reaction?
Colour change
Gas being produced
Solid forming (precipitation)
An energy change
What happens during an exothermic reaction?
Heat is released
What happens during an endothermic reaction?
Heat is absorbed
What always happens in any chemical reaction?
A new substance is formed
How can you monitor a reaction?
Change in mass
Volume of gas released
If a reaction produces gas the mass of reactants will?
Decrease
What are two apparatuses that measure the volume of gas produced in a reaction?
Collection of gas using a syringe
Collection of gas over water
In a line graph that has 3 points from start middle and end what happens at stage A?
A slope is at its steepest here indicating that a lot of gas is being released indicating that the reaction is fast
In a line graph that has 3 points from start middle and end what happens at stage B?
the slope is less steep here indicating that the reaction is slowing down.
In a line graph that has 3 points from start middle and end what happens at stage C?
the graph has levelled off. No more gas is being produced hence the reaction has stopped
How can the rate of a chemical reaction be increased?
Increasing temperature
Increasing concentration of reactant
Increasing surface areas/decreasing particle size
Using a catalyst
When you increase the temperature what happens?
An increase in collisions between particles (faster reaction)
When the concentration of reactants is increased what happens?
there are more reactant particles moving in the same space and therefore increases the number of collisions.
The higher the concentration the ______ the reaction
Faster
The _______ the particle size and therefore increased surface area, the faster the reaction.
The ______ the particle size and therefore decreased surface area, the slower the reaction.
Smaller, bigger
Concentration can only be changed if reactants are a?
Solution
Surface area/particle size can only be changed for reactants that are?
Solid
What are catalysts?
Substances that speed up a reaction without getting used up and can be recovered at the end of
When comparing rate of reaction line graphs the steeper the line the _____ the reaction?
Faster
When comparing rate of reaction line graphs the flatter the line the _____ the reaction?
Slower
Protons have what charge?
One-positive
Neutrons what what charge?
Neutral
Electrons have what charge?
One-negative
Protons and neutrons have what mass?
One mass unit
