p1 changes of state Flashcards
what is the definition of density
the amount of mass in a certain volume
how do you calculate density
density = mass / volume
why is a solid of a substance denser than a gas of the same substance.
1 cm cubed of a solid state has much more particles than 1 cm cubed of a gas
what is conservation of mass
this law states that no mass will be lost in the physical change eg 1 gram of ice will melt into 1 gram of water
what is temperature
how hot or cold something is measure in degrees celsius
what is energy measured in
(J) joules
state two things that happen when you heat things up
the state can change eg solid to liquid
or it can speed up reactions.
what is the specific heat capacity (J/Kg)
the energy needed to raise the temperature of a 1 kg substance by 1 degree
how do you work out the specific heat capacity (J/Kg)
change in thermal energy (J) = mass (Kg) * specific heat capacity (J/Kg) * change in temp (degrees Celsius)
what is specific latent heat and how is it measured
the amount of energy needed to change the state of one kg of a substance (J/Kg)
what are the 2 types of specific latent heat
fusion and vaporisation
fusion = energy need to change solid to liquid
vaporisation = energy needed to change liquid to gas
how do you calculate specific latent heat (J/Kg)
thermal energy needed for a change in state (J) = mass(Kg) * specific latent heat (J/Kg)
why does the balloon get larger as air is blown into it
because as the air particles hit the inside of the balloon they exert a forces the more particles the higher the force
how does temperature effect gas pressure
the higher the temperature the higher the pressure. this is because the particles have more energy so move around more increasing the pressure exerted on the inside of the object
how is pressure measured
pascals (Pa) 1 Pa = 1 N/m^2
what is absolute zero in terms of pressure
the lowest pressure a gas can exert
how are pressure and volume linked
as volume increases pressure decrease
as volume decreases pressure increases
they are inversely proportional
what is the equation involving pressure and volume in terms of gas
pressure (Pa) * volume (M^3) = constant
what is atmospheric pressure
the pressure exerted by the weight of the atmosphere
explain why a can would collapse when air is removed from inside
because the pressure are now unbalanced because there is a lower pressure inside the can than outside causing it to collapse
what happens to air pressure when you go high up
pressure decreases
what happens to liquid pressure as you go deeper
pressure increases
how do you calculate liquid pressue
pressure = height of column * density of liquid * gravitational field strength
how do calculate pressure
pressure = force divided by area
