science unit 3 revision Flashcards
(40 cards)
what are the factors that affect diffusion
temperature
molecule size
surface area
distance
concentration
what is a hypothesis?
a prediction of what is going to be happen based on scientific knowledge
what is a null hypothesis?
a prediction that states no difference between two variables
what are the factors which affect enzyme action?
temperature
concentration
surface area
catalyst
Ph
how does temperature affect diffusion?
the more temperature, the more the particles will have more kinetic energy
how does molecule size affect diffusion?
the smaller the molecule, the faster the diffusion happens. The bigger the molecule, the slower diffusion happens
how does distance affect diffusion?
the further the molecule has to travel, the longer diffusion will take, the shorter the distance, the faster diffsusion happens
What are the factors which affect plants?
light intensity
temperature
pH
mineral ions
how does temperature affect enzyme action?
increase in temp means that there is more kinetic energy
more collisions between substrate and enzyme
more substrate complexes
how does concentration affect enzyme action?
increasing concentration means the rate of reaction increases because of more collisions
how does pH affect enzyme action?
at optimum ph, the enzyme works at it’s best
However, as the pH decreases, the enzyme denatures
enzyme below pH, more H plus ions
enzyme higher or above pH, more OH minus ions
What is fuel?
A potential store of chemical energy which can be burned through oxygen
What is the combustion equation?
Fuel+ oxygen-energy+carbon dioxide+water
What is hydrocarbon?
A mix of hydrogen and carbon atoms
What are two types of fuel?
Alkanes and alcohol
What is the formula for alkanes?
CnH2n+2
What is the formula for alcohols?
CnH2n+OH
What is crude oil?
This is a mixture of alkanes
The fuels which are higher in the fractional distillation column, what does it mean?
It means they require less energy
It does have a high boiling point
The field which are lower in the fractional distillation column, what does it mean?
That they require lots of energy
More carbon atoms are needed
What is the boiling point of fuels at the bottom?
350 degrees
What is the boiling point of fuels at the top?
40 degrees
What does voltmeter measure?
Voltage
What does an ammeter measure?
Current
