CHAPTER 1- MATTER THEORY Flashcards
What is Kinetic Theory?
Scientist believe that all matter are made of tiny particles, that are in CONSTANT MOTION.(because of the kinetic energy they contain)
These particles can be ATOMS, MOLECULES OR IONS.
This idea is called Kinetic Theory.
What is matter?
Matter is anything that has mass and volume.
That is, matter is anything that requires energy to accelerate or change its motion and which also takes up space.
Matter can come in many forms, but there are four main phases or states of matter: solid, liquid, gas, and plasma.
Since matter is also composed of atoms, these phases differ in the behavior and organization of their atoms.
What is Diffusion?
Diffusion is the movement of particles from an area of high concentration to an area of low concentration until the particles are evenly distributed.
This process occurs in both GASES and LIQUIDS
What is Osmosis?
Osmosis is the movement of water particles from an area of high water concentration to an area of low water concentration, through a semi-permeable membrane.
What are STATES OF MATTER?
All Matter are composed of particles.
Matter can be divided into SOLIDS, LIQUIDS and GASES.
Recently, Scientists have proposed another state of matter called PLASMA.
What is melting?
Melting is the change of a solid into a liquid when heat is applied.
WATER MELTS AT ZERO DEGREES/
What is Freezing?
The process through which a substance changes from a liquid to a solid.
All liquids except helium undergo freezing when the temperature becomes sufficiently cold.
Liquid —-Solid This is called the freezing process ( liquid needs to be cooled off, for example freezing of water, liquid on losing heat to surroundings cools off to form solid.)
WATER FREEZES AT 0 DEGREES
What is Sublimation?
This is when a solid changes directly into a gas without turning into a liquid into a liquid first.
Example: Dry Ice, Iodine, Ammonium Chloride
The picture is dry ice.
Solid —–> Gas This is called the sublimation process ( solid needs to be heated, for example leaving dry Ice on the surface, solid dry ice gains heat from surroundings and turns into gas.
What is Boiling?
Boiling or the boiling point is the temperature when a liquid will have vaporization occurring through the entire liquid (not just on the surface).
This occurs when the liquid’s vapor pressure equals the atmospheric pressure.
WATER BOILS AT 100 DEGREES
What is Evaporation?
Evaporation is a process by which a substance changes from a liquid state to a gaseous state at temperatures below the boiling point of the liquid.
In nature, evaporation—especially from the oceans—plays a key role in the water cycle by moving water from its liquid state on Earth’s surface to the atmosphere as water vapor.
The rate of evaporation depends on the temperature difference between the surface of the liquid and the air.
The greater the difference in temperature, the faster evaporation occurs.
Liquid —> Gas This is called evaporation process ( liquid needs to be heated, example evaporation of water, water on taking up heat from the flame or from the surroundings changes to gas)
What is Condensation?
Condensation is when a gas turns into a liquid.
Condensation is defined as the removal of heat from a system in such a manner that vapour is converted into liquid.
Gas —> Liquid This is called condensation process ( gas needs to be cooled, example condensation of steam on the mirror, when one throws steam on mirror or cold surface, steam or gas loses heat to the surface and changes to gas)
What is Melting Point?
The melting point is the temperature at which a solid melts to form a liquid or liquid freezes to form a solid.
Solid —–> Liquid This is called the melting process ( solid needs to be heated, for example melting of butter, solid on taking up heat changes to liquid)
WATER MELTS AT ZERO DEGREES
What is the Boiling Point?
The boiling point is the temperature at which a liquid boils to form a gas or a gas condenses to form a liquid.
What is the Heating Curve?
If a solid is heated, it melts and eventually boils.
If the temperature is taken at regular intervals as this is done, a heating curve is obtained.
What is Cooling Curve?
A cooling curve of a substance is a graph of the variation of the temperature with time as it is allowed to cool.
The gradient of the cooling curve is related to the heat capacity, the thermal conductivity of the substance, and the external temperature. The more heat is required to change the temperature of the substance, the slower it cools, so the smaller the gradient of the curve. The higher the thermal conductivity, the faster heat is transferred, so the faster the substance cools.
Liquids usually have the highest heat capacity of the phases.
The lines are curved because as the substance cools, the temperature difference between the surroundings and the substance is reduced. This reduces the rate at which heat is transferred out of the substance, reducing the rate of cooling.
Describe an experiment to show diffusion.
In the experiment, there was a high concentration of food coloring particles in the drop of food coloring.
The particles diffused from this area of high concentration to distribute themselves evenly in the beaker of water.
Describe an experiment with Diffusion in GASES.
Diffusion can also be observed in gases.
When a jar filled with brown bromine vapour is allowed to mix with another jar containing air particles, bromine vapour spreads into the two jars. (Figure 1.2.)
Particles of bromine move from a high concentration to a low concentration until they are evenly distributed.
Describe an experiment to explain Osmosis.
You should notice that the level of liquid in the thistle funnel rose.
This occurred because the water particles moved from an area of high concentration inside the funnel.
The semi-permeable membrane has very tiny pores. These are big enough for water particles to pass through but too small for the larger sugar particles to pass through.
Describe an experiment showing the Brownian Motion.
In 1827, the botanist Robert Brown using a high-powered microscope observed the CONSTANT IRREGULAR MOTION OF POLLEN FLOATING ON WATER.
He called this Brownian Motion.
This motion can be explained in terms of kinetic theory.
Air and water particles are constantly moving.
Explain how these phenomena provide evidence for the kinetic theory.
All of the phenomena described in this lesson can only be explained in terms of the kinetic theory.
If substances were not made up of constantly moving particles, then diffusion, osmosis and Brownian Motion could not occur.
Explain the difference between Solids, Liquids, and Gases in terms of energy and arrangement of particles.
In the Solid, the particles are very close together in a very ordering fashion.
In the Liquid, the particles are further apart and in a less orderly fashion.
In the Gas, the particles are very far apart and are haphazardly arranged.
In the Solid, the forces of attraction between particles are strong so that the movement is limited to vibrating around a fixed point.
In the Liquid, the forces of attraction are weaker so the particles are able to slip slowly over each other.
In the Gas, the forces of attraction between particles are so small that particles are able to move freely in all directions and at high speeds.
Explain the following in terms of the kinetic theory of matter:
When a few drops of red colouring are placed in a beaker of water, after a short while, the entire liquid is red.
Food coloring illustrates diffusion in water.
Diffusion is the mixing of molecules due to their random motion, whether in a liquid or a gas.
Because molecules in cold water have less kinetic energy than in warm water, the diffusion process is much slower than in warm water.
The following diagram shows what happens when two gases are allowed to mix.
a. Name the solutions in A and B.
b. Which gas moved faster?
c. Name the process taking place in the tube?
d. Using the kinetic theory of matter, explain the formation of the ammonium chloride ring.
a. Solution A is Concentrated Ammonia and Solution B is Concentrated Hydrochloric Acid
b. The Ammonia travels faster because it contains smaller, lighter particles which make it travel faster. Hydrogen chloride has larger and heavier particles. Hence making the Ammonia diffuse at a faster rate.
c. The process taking place in the tube is DIFFUSION.
d. The ring is not at the center of the tube because smaller lighter particles like ammonia travel faster than heavier particles like hydrogen chloride. The ammonia diffuses faster.
Complete the following diagram by naming the processes that take place at a, b, c, d.
A substance can exist in any state.
The state it takes depends on the temperature and pressure.
These conditions affect state by changing the amount of energy available in the particles in the substance.
Greater energy means that the particles can break bonds and move about more vigorusly.
What are the changes that take place during Boiling?
Does it take in energy or does it give out energy?
When water boils, it means that energy is ADDED so energy is taken in.
What change in matter happens when energy is added or removed?
When energy is added,solid will melt into liquid or liquid will change into gas. (When energy is added it gains heat).
When energy is removed, the liquid will turn into solid or the gas will turn into liquid. (When energy is removed the heat will lose).
The following heating curves were obtained on heating two solids A and B until each was completely melted.
Classify A and B as pure or impure giving reasons for your answers.
If the substance is PURE, the melting point and boiling point remain CONSTANT until the substance has completely changed state.
In A, the substance is IMPURE
In B, the substance is PURE, since the temperature remained constant until it changed states.
TO DOUBLE CHECK THIS ANSWER
A substance C was heated until it had melted.
It was then allowed to cool.
While it was cooling, the temperature was taken every 2 mins.
The results are shown in the table below.
a. Plot a graph of temperature vs time for the data given.
b. Determine the melting point of C.
b. The Melting point of substance C was at 10 seconds.
To double check answer
