Chapter 6- Matter Flashcards
what is density?
how tightly packed the matter is in a given space
density equation
density= mass/volume p=m/v
density (Kg/M^3, g/cm^3)
mass(Kg)
volume= cm^3, m^3
What is the law of displacement?
Law of Displacement -an object completely submerged in a fluid (like water) will replace an amount of fluid equal to its own volume
what happens to mass when the state changes(conservation of mass)
stays the same because the number of particles is the same
what is specific heat capacity?
energy required to increase 1 kg of a substance by 1 degrees Celsius
what is specific latent heat?
the amount of energy required to change the state of 1kg of a substance at a constant temperature
latent heat equation
energy=mass x specific latent heat
SLH = J/k Mass = Kg Energy = J
what is latent heat /
the energy transferred to a substance without the substances temperature rising
What is density?
The amount of mass in a fixed volume how tightly compacted matter is
Density equation
P=m/v
Units for density
g/cm^3
Kg/m^3
Why do objects float
Because they have a low mass of matter in a volume this means they have a low mass of matter in a volume so this means they have a less density than the liquid, this means the object floats in addition an up thrust force causes this
What is sublimation?
Solid to gas
What is deposition?
Gas to solid
What is freezing ?
Liquid to solid
What is evaporation?
Liquid to gas
What is melting?
Solid to liquid
What is condensation ?
Gas to liquid
Solids characteristics
Particles vibrate aroun a fixed point, with little energy , particles re regularly arranged and are tightly compacted , strong bond of attraction
Liquid characteristics
Particles are close, the particles move round each other , they are randomly arranged and have greater energy than solids
Small forces of attraction
Gases characteristics
Particles are far apart
Particles are randomly arranged
Particles move quickly in all directions
High energy
No forces of attraction / weak forces of attraction
Required Practical 5. Density of regular and irregular solid
- Firstly measure the mass of regular solid
using a balance - Note the mass in a table
- using vernier calipers measure the length, width and
height of the object - multiply the length width and height to
calculate the volume of the object
5-now calculate the volume of the object us, the
equation density- mass ÷ volume. - Repent steps 1-5 3 more times and calculate
a mean - Now measure the mass of an irregular solid
using a balance. Record the mass - To calculate to value, fill an Eureka (displacement) with water until the water is level( use a measuring cylinder(not that relevant)
with the spout. - Place a measuring cylinder below the spout
- Lower the irregular solid into the Eureka (displacement) can slowly
- The water displaced into the measuring cylinder is the volume of the solid
- measure (read) the value of water displaced and note this down
- Use the volume and mass to calculate
the density using density= mass/volume - Repeat 3 more times at calculate a mean
- write a conclusion
What is the conservation of mass?
When a substance changes state its mass is the same as the number of particles is the same
Mini practical- Finding the melting point of stearic acid
Place solid stearic acid in a boiling tube with a thermometer inside(the acid)
Record staring temperature using a thermometer
Place test tube in a beaker contains water(water bath)
Heat with a Bunsen Bruner , start a stop clock and measure the tempearture using the thermometer every minute
Remove from hot water once all the acid melts, record the final temapetaturE this is the melting point
Repeat 3 more times and calculate a mean
(To work out melting point)
Plot a graph with the results
How would you calculate the density of a liquid
Place a measuring cylinder on a balance tear the balance fill the measuring cylinder with the liquid, not the mass of the liquid, note the volume of the liquid , use the equation mass +density/volume to calculate the density
What is internal energy?
The total energy that a systems particles have in its potential and kinetic energy stores
How does increasing the temperature of a system/substance increases the internal energy
More work is done , the energy causes the particles to move and increases the kinetic energy
How does the energ in a substance relating to internal energy have relationship
The potential energy that they hav in their individual positions are relative to eachother
When
When hay’s all state of a substance changes so does the energy of the particles
What is specific latent heat?
Te amount of energy require to change 1kg f a substance from one state to another without changing its temperature
Can be either fusion(s to l or l to s) or vaporisation (l to g or g to l)
What does latent mean?
Hidden
What is latent heat
It is hidden heat it refers to changing state of a substance without raising it’s temperature
What happens to energy and internal energy when a substance is melting or boiling?
Energy is till put in but it’s internal energy is increasing , but the energy used to break bonds rather than raising the temperature
What happens to energy and internal energy when a substance is freezing or condensing
Bonds are formed between particles with relative energy . This mean the internal energy decreases , but the temp doesn’t go down until all th substance has turned to liquid(condensing) ir a solid
Specific latent heat equation
E=lm
L is lattent heat units for this are J/kg
M is mass
E is energy
How is kinetic energy related to temp (in gas)
The avg energy in ek stores is related to temp, higher them higher ek in a systems store
What is a system?
object or group of objects.
If temp increases how does it affect motion in gases
If temp increase this increases energy in kinetic energy stores which mans the particles move faster
Side note
If this is in a closed system Thi will increase prsssure as there i more frequent collisions of particles per an area
Why does a balloon push out as it rises in the atmosphere?
The atmospheric pressure outside the balooon is lower than the pressure inside the ballon as the balloon goes up this mans the pressure is cgreater on the inside than the outised spa ding the balooon , this it the same for a marshmallow
How is pressure created in gases
Through collisions of gas ateiclea with a surface
If the temp is constant and volume is increased the pressure decreases , in a eagled container th pressure is always the total force exerted by all gas particle on a unit o are of the container walls
If work is done it will increase pressure as this energy is transferred to ek stores increasing speed due to 1/2 x mas. X velocity^2. Which means there are more collision over a unit of area increasing the pressure
Pressure volume constant
Pressure and volume are in an inversely proportional relationship
Pv= constant
If volume increases pressure decreases
But the constant stays the same value
For example
Pressure = 100 pa
The volume decreases to 0.3cm^3 from 1.5 cm^3
The temp and mass stay the same what is the pressure
I
What is the pressure
100 x 1.5= 150
So p x 0.3= 150
P= 150/0.3
P= 500 pa
