The Basics of Chemistry
Matter, Energy, and Reactions
Metrics Review
Matter- The “Stuff” of Science
Science- The “Stuff” we are learning
•The system of knowledge used to learn about the world around us.
–The ______
–Lots of different “steps”– depends on who is teaching.
•5 Common Steps:
–______, ______, ______, ______, ______
Properties of Matter
•Matter has two characteristic ______:
•______are independent properties of matter. They are definable through various types of______:
•Density, ______, odor, ______/______, malleability, ductility, ______.
Properties of Matter
•______define how matter acts with other matter.
•Gold does not ______. Nitrogen does not ______. Sodium reacts ______with water. Water can be broken down with ______.
Physical Changes
•Changes the ______property of a substance, not the ______of the substance.
•Examples:
–Painting (the object remains the same)
– ______
–Ripping paper
-- ______
Chemical Changes
•Changes the ______, ______, and/or ______of atoms in a substance.
•Examples:
–Sodium + Chlorine Salt
–Iron + Oxygen Rust
-- CO2 + H2O Sugar + O2
•Key: The substances have changed
Continuous Theory of Matter
All matter is made up of ______, which are in turn made up of ______and ______particles.
Quarks: Too Small for Us
•Though there is proof they exist, we are not going to be concerned about them in Chemistry.
______
•However, we know lots about. You will be expected to know a lot about them all.
Subatomic Particles
•______: Positive charge; mass of 1 amu. Located in the ______.
•______: No charge (0); mass of 1 amu. Located in the ______.
•______: Negative charge; 1/1837 amu (Count it as ______!)
–Located ______the nucleus.
–About 99.9% of the ______of an atom.
Subatomic Particles
•The ______:
–Designated in the periodic table by ______.
–The number of protons also tells the amount of positive ______in an atom.
–The proton determines the ______.
–Every Oxygen atom has ______protons, for example.
•This is a ______; there are no exceptions to this ______.
Subatomic Particles
•The neutron: Designated by ______minus atomic number in the periodic table.
•Atomic mass is the total number of ______plus ______in an atom.
•Neutrons may vary in an element. Variable numbers of neutrons among one particular element are called ______.
•______have different masses than other ______of the same ______.
Subatomic Particles
•The ______: The most important part of an atom, at least for ______sake.
•Since we assume all elements have a ______charge, then the # of ______= the #of electrons.
•We can represent an electron with: ______
Subatomic Particles
•______have been theorized in many different forms; you will learn more in a later unit.
•Electrons are responsible for ALL ______and ______.
•Chemical ______occur in order for electrons to achieve a more ______arrangement in an atom.
Chemical Reactions
•Always involve a change in ______and the formation of ______. This is also called a ______!
•Always cause two things:
1. A change in ______
2. ______formed
•And either one of two things:
1. A release of ______(a drop in H, or ______)
2. An increase in ______(increase in S, or ______)
Physical and Chemical Changes
•Some important examples of chemical changes:
Combustion (only ______)
Digestion
Protein ______
Acid/base ______
Simple ______
______
______
Chemical Changes:
If you take nothing else, take this:
•Chemical changes will ______alter the ______properties of matter.
•Iron doesn’t have the same strength after it has been ______. ______is no longer breathable, either. But ______and ______are still there- in the form of______.
•Remember: A chemical change will always have an energy change- and NEW SUBSTANCES ARE FORMED
Reaction Laws
•There are two laws involved with Chemical Reactions:
•1. The law of ______of ______-
•2. The law of ______of ______-
Chemical Equations
•Based on the 2 laws just presented:
•Each ______of a chemical equation must be ______to the other!
Chemical Equations
1. “Sides”
–Sides are divided by the ______--
–To the left; the______
–To the right; the ______.
–The arrow, then, says:
–“______to ______”
2. “Symbols”
–There are many symbols:
______-- DUH!
Na; O; H; Cl
(j) or (cal)
2 ______
2 ______
Just Because It’s Important:
•Don’t forget why ______occur:
–So e- can achieve a more ______state
•Don’t forget what happens when a ______occurs:
–______
–______changes form
Classifying Matter
•______can be:
•1. ______.
•Found on the ______. Easily recognized through their various properties.
2. ______
•Substances with recognizable characteristics that are different than the properties of the matter that makes them up.
Elements are made up of…
•Electrons and protons determine the ______of the various elements.
•Electrons make ______reactive, so that it can’t be found by ______in nature; ______make it a lightweight metal that actually ______on water.
•Protons and electrons make ______so unique and vital to life.
Compounds
•Compounds are ______paired together after a chemical reaction.
•Compounds will ALWAYS occur in the same ______for each unique compound.
•Compounds will have ______unique to the compound.
•______and ______are distinctly gases; but combined, they create water, a liquid…
•The Law of ______:
Mixtures
•Mixtures:
•1. Do not have ______.
•2. The ______of individual parts of a mixture remain the same.
•If you change conditions, the ______substances will change accordingly.
•Can be ______(solid + liquid, for example)
Phases of Matter
•The Phases of Matter are related directly to the amount of ______the matter contains.
–______occurs in 2 forms:
•______:
•______:
•Phases are determined by how much ______the matter has.
•There are 4 phases of matter: ______, ______, ______, and plasma.
–Some say plasma is NOT a form of matter; we will count it.
Phases of Matter
•The first phase of matter is ______.
–The most orderly form of matter.
•Shape:
•Volume:
•Energy:
•Entropy:
Phases of Matter
–______are the next phase of matter.
–The second most orderly form of matter.
•Shape:
•Volume:
•Energy:
•Entropy:
Phases of Matter:
•______are the third phase of matter
•The least orderly and most energetic of the phases found on earth.
–Shape:
–Volume:
–Energy:
–Entropy:
Phases of Matter:
•______are the next phase of matter.
•They are found only in stars and, in theory, fusion reactors. The least orderly form of matter.
–Shape:
–Volume:
–Energy:
–Entropy:
Phases of Matter
Phase changes can be shown on a graph in an easy way: this is called the ______.
Phase Change Diagram
•______does not change during a phase change– but ______does.
•Instead of the e! adding to ______, e! is used to break attractions between molecules.
•In ice, e! works to vibrate the molecules ______. In water, it works to spread the molecules out far enough that their density ______enough to escape into the air.
Energy (e!)
•Energy is defined as the ______.
–______energy is the energy of motion.
•Heat
•Light
•Motion
–______energy is the energy that is “stored” by position.
•Chemical bonds
•“Positioned” objects
Reaction Types: Energy
______Reactions that release kinetic energy.
______Reactions that absorb kinetic energy and convert it to potential energy.
The Energy of Chemical Reactions
•Every ______(and therefore, compound, mixture, etc.) has ______energy– usually from the position of its electrons.
–This energy can be measured using a method called ______.
–The calorimetric numbers can be used to calculate the ______of a given reaction.
–Exothermic reactions are given ______numbers
–Endothermic reactions are given ______numbers
Potential Energy Diagrams
1. ______: E! final > E! initial
2. ______: E! final < E! initial
3. ______: E! act ______first ridge
HCl + NaOH H2O + NaCl
•Knowing the amounts of heat released or absorbed by each chemical, it becomes possible to calculate the energy of the reaction.
•Hess’s Law:
–The sum of the ______of the products minus the sum of the ______of the reactants equals the enthalpy of the reaction system OR:
–(∑∆H(______) - ∑∆H(______) ) = ∆H(______)
Measuring In Chemistry
•HCl= -22 kcal…?
–How much HCl does it take to ______22 kilocalories?
–1 HCl? 1 Million? More? Less?
The Mole
•Predicted by ______, the MOLE is used to measure amounts of particles in Chemistry.
•In 16 grams of Oxygen, there is ______of oxygen atoms.
•In 1 gram of Hydrogen, there is ______of hydrogen atoms.
•Moles are a ______used to measure masses of atoms in ______
So, HCL= -22 kcal
•Should actually read:
HCl = -22 kcal/ mole
•That means it takes ______molecules of HCl to release 22 kcal of energy.
•ONE HCl releases ______/______.
•One MOLE HCl releases almost as much heat as your body produces in an entire day.
•Moles are ______
Dimensional Analysis
•The math of chemistry (and many ______
•This is a way of changing the labels of given ______into usable ______.
•The most common type we will use is changing from ______to ______, or vice-versa.
Dimensional Analysis
•Dimensional analysis is a fancy way of saying that we will be changing the ______of numbers by changing the ______of the labels.
•You also use this at the gas pump when figuring the ______of your fuel.
For Chemistry
•Moles are the ______:
–32 g Oxygen is how many ______?
More Measuring
•Correct ______in the lab is very important for ______and ______.
•Many different ______are used, but there are few common ideas to keep in mind when measuring:
Places, everyone, places:
•Whatever unit your tool is ______to measure, you should be able to ______that place!
–Example:
•Ruler marked to measure ______:
–Report to the ______of a mm
Meniscus
•When measuring ______, use the ______(at least for water, and water solutions)...
It’s the ______of water
•Due to the fact the fact that ______is attracted to the ______.
•______measure from the ______of the meniscus when measuring volumes of water or water solutions.
Always Report Correctly
•Your observations ______as you see them.
•Sometimes labs ______like they are supposed to; that’s fine.
–But you must ______report the results YOU see, not the results you ______!
Significant Digits
•A way of accounting for ______when measuring.
–This means you have a margin of error when performing calculations
•ALL ______in Chemistry class need to be reported with the correct number of significant digits.
Sig Fig Rules:
•All ______numbers are significant.
•______between ______numbers are significant.
Examples:
46 = 2 sig figs
503 = 3 sig figs
13.00068 = 7 sig figs
More Sig Fig Rules
•Zeroes after a non-zero number are NOT significant…
12000 = ______
•UNLESS you add a ______…
12000. = 5 sig figs
•OR the ______come after the ______itself:
12.000 = 5 sig figs
STILL more…
•Zeroes ______a non-zero number are NOT significant…
0.0004 = 1 sig fig
But you can MAKE them significant by adding a ______
______= 3 sig fig
Scientific Notation
•Used to show large numbers
6.02 x 1023
•Also used to show significant digits
6.02 x 1023 = 3 sig figs
3.00 x 10-2332453453523452345 = 3 sig figs
•Another helpful rule:
–If a zero can be omitted by using scientific notation, it’s probably not significant!