NO !! What is Chemistry ? Def’d 1 – the branch of science that deals with the identification of the substances of which matter is composed; the investigation of their properties and the ways in which they interact, combine, and change; and the use of these processes to form new substances Def’d 2 – the complex emotional or psychological interaction between two people NO !!

Windsor University School of Medicine States of matter ”Success is not the key to happiness. Happiness is the key to success. If you love what you are doing, you will be successful”. Albert Schweitzer Ch.1 J.C. Rowe

Chapter 1 – States of Matter What is Matter? Matter is anything that has mass and occupies a space There are three major types of matter in our universe Solid Liquid Gas Plasma How can we tell the 3 states of matter apart All 3 have different physical properties

The Four States of Matter Basis of Classification of the Four Types Based upon particle arrangement Based upon energy of particles Based upon distance between particles

STATES OF MATTER LIQUID PLASMA SOLID GAS Tightly packed, in a regular pattern Vibrate, but do not move from place to place Close together with no regular arrangement. Vibrate, move about, and slide past each other Well separated with no regular arrangement. Vibrate and move freely at high speeds Has no definite volume or shape and is composed of electrical charged particles

What kind of changes does matter undergo? All matter, regardless of state, undergoes physical and chemical changes. These changes can be microscopic or macroscopic.

What is a physical change? A physical change occurs when the substance changes state but does not change its chemical composition. For example: water freezing into ice, cutting a piece of wood into smaller pieces, etc. The form of appearance has changed, but the properties of that substance are the same (i.e. it has the same melting point, boiling point, chemical composition, etc.) Definition of physical changes.

Characteristics of Physical Changes Melting point Boiling point Vapor pressure Color State of matter Density Electrical conductivity Solubility Adsorption to a surface Hardness Physical changes are characterized by the following:

What are chemical changes? A chemical change occurs when a substance changes into something new. This occurs due to heating, chemical reaction, etc. One can tell a chemical change has occurred if the density, melting point or freezing point of the original substance changes. Many common signs of a chemical change can be seen (bubbles forming, mass changed, etc). Definition of chemical change.

Characteristics of Chemical Changes Reaction with acids Reaction with bases (alkalis) Reaction with oxygen (combustion) Ability to act as oxidizing agent Ability to act as reducing agent Reaction with other elements Decomposition into simpler substances Corrosion Chemical Changes are characterized by the following:

Intensive and Extensive Properties Physical and chemical properties may be intensive or extensive.

What are intensive properties? Intensive properties such as density, color, and boiling point These properties do not depend on the size of the sample of matter and can be used to identify substances.

What are extensive properties? Extensive properties such as mass and volume do depend on the quantity of the sample.

How can we identify physical properties? Physical properties are those that we can determine without changing the identity of the substance we are studying.

Examples of physical properties: The physical properties of sodium metal can be observed or measured. It is a soft, lustrous, silver-colored metal with a relatively low melting point and low density. Hardness, color, melting point and density are all physical properties.

What are chemical properties? Chemical properties describe the way a substance can change or react to form other substances. These properties, then, must be determined using a process that changes the identity of the substance of interest.

How can chemical properties be identified? One of the chemical properties of alkali metals such as sodium and potassium is that they react with water. To determine this, we would have to combine an alkali metal with water and observe what happens. In other words, we have to define chemical properties of a substance by the chemical changes it undergoes.

Comparison of Physical and Chemical Properties

Conservation of Matter Law of Conservation of Matter There is no observable change in the quantity of matter during a chemical reaction or a physical change. In other words, matter cannot be created nor destroyed. It is just converted from one form to another Definition of Conservation of matter.

(And how the Kinetic Molecular Theory affects each) States of Matter (And how the Kinetic Molecular Theory affects each) Solids Liquids Gases Plasma

States of Matter

Solids have an infinite number of free surfaces. Have a definite shape Have a definite volume Solids have an infinite number of free surfaces. Kinetic Molecular Theory Molecules are held close together and there is very little movement between them.

Liquids Have an indefinite shape Have a definite volume Liquids have one free surface. Kinetic Molecular Theory: Atoms and molecules have more space between them than a solid But less than a gas (ie. It is more “fluid”.)

Have an indefinite shape Have an indefinite volume Gases Have an indefinite shape Have an indefinite volume Kinetic Molecular Theory: Molecules are moving in random patterns with varying amounts of distance between the particles.

Kinetic Molecular Model of Water At 100°C, water becomes water vapor, a gas. Molecules can move randomly over large distances. Between 0°C and 100 °C, water is a liquid. In the liquid state, water molecules are close together, but can move about freely. Below 0°C, water solidifies to become ice. In the solid state, water molecules are held together in a rigid structure.

Changing States Changing states requires energy in either the form of heat. Changing states may also be due to the change in pressure in a system. Heat of formation, Hf. Heat of vaporization, Hv

SOLID GAS LIQUID CHANGES OF STATE sublimation Melting Boiling Condensation Freezing LIQUID

Plasma Plasma is by far the most common form of matter. Plasma in the stars and in the tenuous space between them makes up over 99% of the visible universe and perhaps most of that which is not visible. On earth we live upon an island of "ordinary" matter. The different states of matter generally found on earth are solid, liquid, and gas. We have learned to work, play, and rest using these familiar states of matter.

On August 31, 2012 a long prominence/filament of solar material that had been hovering in the Sun's atmosphere, the corona, erupted out into space at 4:36 p.m.

Plasma Cont. Sir William Crookes, an English physicist, identified a fourth state of matter, now called plasma, in 1879. Plasma temperatures and densities range from relatively cool and tenuous (like aurora) to very hot and dense (like the central core of a star). Ordinary solids, liquids, and gases are both electrically neutral and too cool or dense to be in a plasma state. The word "PLASMA" was first applied to ionized gas by Dr. Irving Langmuir, an American chemist and physicist, in 1929.

Plasma Cont. Plasma consists of a collection of free-moving electrons and ions - atoms that have lost electrons. Energy is needed to strip electrons from atoms to make plasma. The energy can be of various origins: thermal, electrical, or light (ultraviolet light or intense visible light from a laser). With insufficient sustaining power, plasmas recombine into neutral gas. Plasma can be accelerated and steered by electric and magnetic fields which allows it to be controlled and applied. Plasma research is yielding a greater understanding of the universe. It also provides many practical uses: new manufacturing techniques, consumer products, and the prospect of abundant energy.

Products manufactured using plasmas impact our daily lives:

EXAMPLES: Computer chips and integrated circuits Computer hard drives Electronics Machine tools Medical implants and prosthetics Audio and video tapes Aircraft and automobile engine parts Printing on plastic food containers Energy-efficient window coatings High-efficiency window coatings Safe drinking water Voice and data communications components Anti-scratch and anti-glare coatings on eyeglasses and other optics

For water sterilization, intense UV emission disables the DNA of microorganisms in the water which then cannot replicate. There is no effect on taste or smell of the water and the technique only takes about 12 seconds. This plasma-based UV method is effective against all water-born bacteria and viruses. Intense UV water purification systems are especially relevant to the needs of developing countries because they can be made simple to use and have low maintenance, high throughput and low cost. Plasma-based UV water treatment systems use about 20,000 times less energy than boiling water!                   

Kinetic Molecular Theory PHASE CHANGES OR CHANGES OF STATE Triple Point—combination of temperature and pressure where all three phases coexist

Kinetic Molecular Theory PHASE CHANGES OR CHANGES OF STATE a to b: solid increases in temperature. b to c: solid melts to liquid at a constant temperature c to d: liquid increases in temperature d to e: liquid vaporizes to gas at a constant temperature e to f: gas increases in temperature

Latent Heat absorbed by a body or any thermodynamic Describes - the amount of energy that is released or absorbed by a body or any thermodynamic system during a time period of constant- temperature. During this period a change of state is often observed

Molar Heats of Fusion and Vaporization Molar heat of fusion: the energy required to melt one mole of a substance. (ΔHfusion) Molar heat of vaporization: the energy required to vaporize one mole of a substance. (ΔHvaporization) ΔHvaporization ΔHfusion

Molar Heat of Fusion: Defined The amount of heat necessary to melt (or freeze) 1.00 mole of a substance at its melting point Note the three important points: 1) It's 1.00 mole of a substance 2) there is no temperature change 3) there is a change of state

Molar Heats of Fusion and Vaporization Molar heat of fusion: the energy required to melt one mole of a substance. (ΔHfusion) Molar heat of vaporization: the energy required to vaporize one mole of a substance. (ΔHvaporization) ΔHvaporization ΔHfusion

Molar Heat of Vaporization: Defined The energy required in calories to completely convert one mole (18g) of water to steam without increasing the temperature is called the latent heat of vaporization. It is called latent heat because the water does not go through a change in temperature as it changes state Please note 2 things: 1) 1 mole of water 2) Liquid to steam (gas / vapour)

Molar Heats of Fusion and Vaporization Calculations Example 1:How much energy is required to melt 10.0 grams of ice into water? The heat of fusion of ice is 1g per 80.0 calories/(gx°C). 10.0 g H2O x 80.0 calories = 800. calories 1 g H2O Example 2: How much energy is required to vaporize 36.02 grams of water to steam at 100°C? Water’s molar heat of vaporization is 6.01 kJ per mole. 36.02 g H2O x 1 mol H2O 6.01 kJ = 12.02 kJ 18.01 g H2O

Specific Latent Heat (L) Defined: This is the quantity of energy in the form of heat (Q) required to completely effect a phase change of a unit of mass (m), usually 1kg, of a substance. Is this an intensive or extensive property ? Specific latent heat follows the formula:

Specific Heat Capacity Calculations The amount of energy needed to raise one gram of a substance by 1°C. Units = J/(gx°C) Use q=mC ΔT here Memorize q = mCΔT

Specific Heat Capacity Calculations q = mCΔT q = heat in joules, J m = mass in grams C = specific heat capacity ΔT = Tfinal – Tinitial Example 1: A 15 gram sample of water is warmed from 45° to 65°C. The specific heat capacity of water is 4.18 J/(gx°C). How much energy was required to warm the water? Answer: q = (15)(4.18)(65-45) = (15)(4.18)(20) = 1254 Joules Example 2: A 2.0 gram sample of metal requires 5.0 Joules of energy to warm from 10 to 20°C. What is the metal’s specific heat capacity? Answer: 5.0=(2.0)(C)(20-10) or 5.0=(2.0)(C)(10) and C = 0.25 J/(gx°C).

Colligative Properties Defined: these are the physical properties of a solution which vary depending on the concentration or ratio of solute particles to the number of solvents in a solution and not on the type of chemical species present Change in Solute ratio induces: - Vapour pressure lowering Boiling Point Elevation Freezing Point Depression Increase in Osmotic Pressure

Colligative Properties Adding impurities to a liquid increases the boiling point and decreases the freezing point (widens the liquid temperature range) Examples: Adding antifreeze to the water in the radiator to prevent boiling in summer and freezing in winter. Putting salt on the road to prevent the road from icing up.

Kinetic Molecular Theory 1. Gases, made up of particles in state of random motion 2. Particles move in a straight line until they collide. 3. Most of any gas is empty space. 4. No Attractive force 5. Elastic collisions 6. Average kinetic energy, temperature dependent

Evidence of Kinetic Theory Diffusion Osmosis

Diffusion Molecules intermingle as a result of their kinetic energy of random motion. Consider two containers of gas A & B separated by a partition. The molecules of both gases are in constant motion & make numerous collisions with the partition. If the partition is removed, the gases will mix because of the random velocities of their molecules. In time a uniform mixture of A & B molecules will be produced in the container. The tendency toward diffusion at room temperature because of the high molecular velocities associated with the thermal energy of the particles.

Diffusion

Osmosis If two solutions of different concentration are separated by a semi-permeable membrane which is permeable to the smaller solvent molecules but not to the larger solute molecules, then the solvent will tend to diffuse across the membrane from the less concentrated to the more concentrated solution. This process is called osmosis. The transport of water & other molecules across cell membranes is essential. The energy which drives the process is usually discussed in terms of osmotic pressure.

Osmosis The movement of the solvent Solute does not move Involves a semi-permeable membrane Usually a passive process

Application to Living Systems Think about spending a long day at the Beach !!