Praxis: Chemistry

IUPAC nomenclature of organic compounds according to their functional groups

* The root word and 1⁰ suffix together is known as base name. * The Prefix(es), infix and 2⁰ suffix may or may not be required always.

Relationship among phases of matter, forces between particles, and particle energy

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Describe the dissolving process

1. The bonds holding the solute particles together must be broken. This bond-breaking step requires energy. 2. The solvent surrounds the solute particles forming bonds (intermolecular or ionic) between the solute and solvent particles. This process is sometimes called solvation, or if the solvent is water, it is called hydration. Since this is a bond-forming step, this process releases energy. 3. Finally, the cluster of solute and solvent particles are distributed evenly throughout the mixture. This process requires energy.

What are the special properties of water?

1. Water has high cohesion. Hydrogen bonds between water molecules make them stick together. But, you already knew that. The reason this is nifty is that it results in high surface tension, or the tendency for water molecules to stick together when at the boundary of a gas and a liquid (or a liquid and a solid, or even a liquid and a liquid...you get the idea), which means that it's actually pretty hard to break the surface of water compared to other liquids. Surface tension is what allows some things to float on water even if they're denser than water. 2. Water is a great solvent. Water is dangerously good at dissolving things. Since water is a polar molecule, its positive end is attracted to negatively charged ions or the negative sides of other polar molecules, and its negative side is attracted to positively charged ions or the positive sides of other polar molecules. If you drop a salt crystal into water, the sodium ion (Na+) will quickly be surrounded by eager water molecules with the negative sides facing the positive sodium ion; the chlorine ion (Cl-) will be similarly surrounded by other water molecules with positive sides facing the negative chlorine ion. The important point is that the Na+ and Cl- get separated from each other, or dissolve in the water. Things that dissolve in water easily are hydrophilic ("water-loving"), and the "dissolvability" property is called solubility. Have you ever tried to mix oil and water? No? Not much of a partier then, are you? It's a humbling experience because everyone fails. Oil is hydrophobic ("water-fearing") and immediately puts a stop to all of this dissolving business. Fats, including oil, are nonpolar molecules. All the component atoms in nonpolar molecules are sharing electrons equally among themselves. No squabbles there. The result, though, is that there is nothing for water to be attracted to, since water, the polar snob that she is, likes either ions or other polar molecules. The take-home point is this: if a substance is not polar or charged in any way, it usually won't dissolve in water (insoluble). You're out of luck, nonpolar molecules. 3. Water acts like a buffer. To understand buffers, we need to know a thing or two about acids and bases. Acids are substances that release hydrogen ions (H+) into solution. HCl, or hydrochloric acid, is a compound formed by ionic bonds. When you drop it in water, the H+ and Cl- come apart, because as we said before, water is polar and will attack charged ions. Cue the paparazzi and/or vulture imagery. As a result, a whole bunch of H+ ions are released into solution, which dramatically increases the concentration of H+. An increase in the concentration of H+ causes an increase in acidity. A base, on the other hand, is a substance that will bind to the free hydrogen ions (H+) that might be floating around in solution. NaOH is an example of a base. Bases are also known as alkaline. When you drop NaOH in water, the Na+ ions become separated from the hydroxide ions (OH-). Even though the oxygen and hydrogen of OH- are bound together covalently, they still count as an ion because, as a unit, they possess an extra electron, and therefore, have a net negative charge. Back to bases. You can probably guess what happens when a stray OH- ion encounters a free H+ ion: it's love at first sight, and the ions bind. What happens as a result? The concentration of free H+ ions in that solution decreases, which increases the basicity. Bases have more OH- ions than acids. To summarize, acids release a bunch of H+ ions into solution, and bases mop them up like they're Swiffer. The last thing to mention before we come back to buffers is pH. The pH scale goes from 1 to 14 and is the way we measure how acidic a solution is, which has to do with how many hydrogen ions are in solution. Pure water has a pH of 7, which is neutral, and has exactly the same number of H+ ions as OH- ions floating around in solution. Two things to remember: 1.If there are relatively more H+ ions, the pH goes down, increasing the acidity. More H+, more acidic, lower pH. 2.If there are fewer H+ ions, the pH increases, increasing the basicity. Less H+, more basic, higher pH. Remember that the pH scale runs from 0 to 14, and each step represents a tenfold difference. In other words, a solution with a pH of 5 is 100 times more acidic than something with a pH of 7. And a solution with a pH of 3 is 10,000 times more acidic than something with a pH of 7. To put this in perspective, soda has a pH of 3. Kind of makes you want to rethink that Big Gulp Coke, doesn't it? Water, as stated at the beginning of this section, can act like a buffer if there is a sudden change in pH. At any given moment, there are a few H2O molecules that break apart and form H+ and OH-. Don't worry...most of the water molecules are still completely bound together. There are a few hydrogen ions here and there who effectively get tired of "sharing" an electron with the pushy, selfish oxygen atoms. They throw their little atomic arms up and shout, "Fine! The electron is all yours. I'm outta here!" Therefore, there are a few stray H+ and corresponding OH- ions floating around in solution. These few dissociated water molecules are what give water its buffering ability. If we add an acid to solution, some of the free OH- ions will bind to the newly added H+ ions, which will moderate the decrease in pH. Similarly, if we add a whole bunch of base to the solution, some of the added base will bind to the free H+ ions in solution, which will moderate the increase in pH. Having said all of this, while water can be a buffer, it isn't a fantastic one since most of the H2O molecules remain completely stuck together. It has a little bit of buffering capability and is helpful with small changes in pH, but it is by no means the best and certainly can't compensate for super drastic changes in pH. 4. Water resists temperature changes. First, water has a high specific heat capacity, which is the amount of energy that it takes to raise the temperature of 1 gram of a substance by 1 °C. In other words, it takes a lot of energy to heat water. Second, water has a high heat of vaporization (the amount of heat required to convert liquid water into gaseous water, aka steam). The high heat of vaporization of water is due to those pesky hydrogen bonds. Water molecules at the surface need to be moving really fast to break free into the air. Heating increases the movement of the molecules, but we already know it takes a lot of energy to heat water because water has a high specific heat. If we put these two concepts together, we find that it takes a lot of energy to heat a water molecule, and we need to heat it a lot to give it the kinetic energy it needs to break the hydrogen bonds holding it to the rest of the water molecules. A double whammy if you're trying to get water to boil. Lastly, water has a high heat of fusion, or the heat you need to take out of water to get it to solidify (freeze). What all this means is that water can hold a lot of heat energy before it changes temperatures and states (solid to liquid to gas). This property of water is great if you are an organism that lives in the water. Why, you might ask? A high heat of fusion means that, even if the temperature of the air changes a lot, water will shelter you from those changes and provide a pretty stable environment. Thanks, water. 5. Ice floats. We know; you knew that. For most compounds, the solid is denser than the liquid, meaning that the solid will sink to the bottom of the container holding the liquid. Not for ice! The point is that water actually becomes less dense when it freezes, which allows the solid form, or ice, to float on the liquid form, or water. This is important for organisms that live underwater. If frozen water sunk, small bodies of water would be more likely to freeze completely in the winter, which would be bad for all the organisms living there. And by bad, we mean certain death. Instead, a layer of ice effectively insulates the underlying water, allowing many aquatic organisms to survive through the winter.

Relationship between energy, frequency, and λ of electromagnetic radiation and electron transition

> energy = > frequency = < λ f=c/λ e=mc²

Moles

A balanced equation has the same amount of ______ as reactants as products. In other words it has equal number of each type of atom on each side.

Effect of presence of catalysts on chemical reaction rate

A higher concentration of reactants leads to more effective collisions per unit time, which leads to an increasing reaction rate (except for zero order reactions). Similarly, a higher concentation of products tends to be associated with a lower reaction rate. Use the partial pressure of reactants in a gaseous state as a measure of their concentration.

Chemical periodicity

A pattern of repeating order of the chemical properties of elements noticed in the mid-1800's by Dmitri Mendeleev, a Russian chemist.

Superunsaturated

A solution which has reached saturation at a higher temperature is supersaturated. Solution containing more solute that the slovent would oringinally dissolve, usually done by heating up the solution.

Electrolytes

A substance that dissociates into ions in solution and acquires the capacity to conduct electricity. Sodium, potassium, chloride, calcium, and phosphate are examples of electrolytes.

Systematic nomenclature

A system for naming inorganic binary compounds that uses the names of two elements/ions in a compound with prefixes to indicate how many atoms/ions are contributed to each molecule or formula unit

Gram atomic mass

Atomic mass of an element expressed in grams.

How to balance chemical reactions

Balancing chemical equations isn't difficult, once you know the way to do it. Start by finding out how many atoms of each type are on each side of the equation. Some teachers recommend making a little table listing the numbers of each atom for the left hand side and for the right hand side. Next, look for an element which is in only one chemical on the left and in only one on the right of the equation. (But it is usually a good idea to leave hydrogen and oxygen until you've done the others first.) To balance that element, multiply the chemical species on the side which doesn't have enough atoms of that type by the number required to bring it up to the same as the other side. The number is called the coefficient. BUT If you have to multiply by, say, 2 1/2, do so, THEN multiply EVERYTHING on each side of the equation by two to get rid of the half. We don't like having halves in equations, as you can't get half a molecule. Now look for the next element or species that is not balanced and do the same thing. Repeat until you are forced to balance the hydrogen and oxygens. If there is a complex ion, sometimes called a polyatomic ion, on each side of the equation that has remained intact, then that can often be balanced first, as it is acts as a single species. The ions NO3- and CO32- are examples of a complex ion. A VERY useful rule is to leave balancing oxygen and hydrogen to the last steps as these elements are often in more than one chemical on each side , and it is not always easy to know where to start. Some people also say you should leave any atom or species with a valancy of one one until the end, and also generally leave anything present as an element to the end. In Example 1 Unbalanced Equation:- C3H8 + O2 ---> H2O + CO2 There are three carbons on the left, but only one on the right. There are eight hydrogens on the left but only two on the right. There are two oxygens on the left but three on the right. Balanced Equation:- C3H8 + 5O2 ---> 4H2O + 3CO2 , you would balance the carbons first, by putting a 3 in front of the CO2, then balance the hydrogens by putting a 4 in front of H2O and finally the oxygens (which are in more than one compound on the right, so we leave them until last) by putting a 5 in front of the O2. Example 2 Unbalanced equation:- H2SO4 + Fe ---> Fe2(SO4)3 + H2 Balance the SO4 first (as it is a complex ion and it is in one chemcial species on each side) 3H2SO4 + Fe ---> Fe2(SO4)3 + H2 Now balance the Fe (which is also in one chemical on each side) 3H2SO4 + 2Fe ---> Fe2(SO4)3 + H2 Finally, balance the hydrogen (although it is in one chemical species on each side, it is usually a good idea to leave it until last) Balanced Equation:- 3H2SO4 + 2Fe ---> Fe2(SO4)3 + 3H2 We alter the coeficients in the equation. Do NOT touch the subscripts for the atoms in a chemical species, or you will change it into an different chemical. That would be a bit like saying I want six chicken legs for a meal, so I'll go get a six-legged chicken. As chickens have two legs, you will need three normal, two-legged, chickens, not a six-legged mutant monster, probably from outer space. If you start by trying to balance something which is in more than one species on one side, you can't easily tell which species you should have more of, and so can end up going round in circles, continually altering things. If this happens, just start again, but balancing atoms or complex ions that are in one species on each side. (This is important or it will not work.)

The effect of buffers

Buffer solutions are used as a means of keeping pH at a nearly constant value in a wide variety of chemical applications. Many life forms thrive only in a relatively small pH range so they utilize a buffer solution to maintain a constant pH.

Saturated

Containing the largest possible amount of a particular solute (single bonds)

What effect does the rate of evaporation have on the size of salt crystals that form when water evaporates from a saltwater solution? (Also, what about the amt of dissolved salt, temperature or amount of space?)

Crystal growth is affected by four naturally occurring factors. It's important to understand what causes crystal growth in order to have an effective solution for preventing it. Here are the four basic reasons in order of significance: Evaporation Time •If the water evaporates very slowly from the solution, over many weeks, relatively few crystals will get started, but these crystals will have time to grow larger before the water is gone. •Conversely if water evaporates from the solution more quickly, more crystals get started, but they don't have time to grow as large. Amount of dissolved salt •The greater the amount of dissolved salt, the greater will be the effect on growth. Larger crystals will normally result from more salt being available. Temperature •The greater the drop in cooling the greater the effect on the size of the crystal. Thus, the greater the drop in temperature, the larger will be the resulting crystals. Amount of space •Crystal size is also determined by the amount of space available for growth. When crystals run out of space and run into one another, they join.

Drawing Electron dot diagram

Drawing the Electron-Dot Formula for Methane, CH4: The first thing that you must do is to determine the number of electrons available for the formula. Hydrogen is in column IA and thus has 1 electron. Since there are 4 hydrogen atoms, the total for hydrogen will be 4 electrons. Carbon is in column IVA and thus has 4 outer electrons...remember that we don't use the atomic number for electron-dot formulas. The total number of electrons for all atoms is 8. The next thing that you must do is to determine which atom will be in the center of the molecule. The next thing that you must do is to draw a "C" and "H" and place 2 electrons between these atoms. All you have to do now is draw all of the other hydrogen atoms around the carbon atom and place 2 electrons between these hydrogen atoms and the carbon atom. This gives you a total of 8 electrons

What is the relationship between the number of a period in the periodic table and the distribution of electrons in the atoms of elements in that period?

Electron shell #1 has the lowest energy and its s-orbital is the first to be filled. Shell #2 has four higher energy orbitals, the 2s-orbital being lower in energy than the three 2p-orbitals. (x, y & z). As we progress from lithium (atomic number=3) to neon (atomic number=10) across the second row or period of the table, all these atoms start with a filled 1s-orbital, and the 2s-orbital is occupied with an electron pair before the 2p-orbitals are filled. In the third period of the table, the atoms all have a neon-like core of 10 electrons, and shell #3 is occupied progressively with eight electrons, starting with the 3s-orbital. The highest occupied electron shell is called the valence shell, and the electrons occupying this shell are called valence electrons.

Avogadro's Hypothesis

Equal volumes of gases at the same temperature and pressure contain equal numbers of particles

Effect of concentration on chemical reaction rate

For many reactions involving liquids or gases, increasing the concentration of the reactants increases the rate of reaction. In a few cases, increasing the concentration of one of the reactants may have little noticeable effect of the rate.

In general terms, what will happen to a chemical equilibrium if the temperature, pressure, or concentration of one of the reactants is changed?

If a chemical system at equilibrium experiences a change in concentration, temperature, volume, or partial pressure, then the equilibrium shifts to counteract the imposed change and a new equilibrium is established. Temperature: When the reaction is exothermic (ΔH is negative, puts energy out), we include heat as a product, and, when the reaction is endothermic (ΔH is positive, takes energy in), we include it as a reactant Pressure: Changes in pressure are attributable to changes in volume. The equilibrium concentrations of the products and reactants do not directly depend on the pressure subjected to the system. However, a change in pressure due to a change in volume of the system will shift the equilibrium. An increase in system pressure due to decreasing volume causes the reaction to shift to the side with the fewer moles of gas. A decrease in pressure due to increasing volume causes the reaction to shift to the side with more moles of gas. There is no effect on a reaction where the number of moles of gas is the same on each side of the chemical equation. Concentration: Changing the concentration of an ingredient will shift the equilibrium to the side that would reduce that change in concentration

Effect of pressure on chemical reaction rate

Increasing the pressure on a reaction involving reacting gases increases the rate of reaction. Changing the pressure on a reaction which involves only solids or liquids has no effect on the rate.

Hydrophobic

Non-polar molecules., Repelling, tending not to combine with, or incapable of dissolving in water.

Examples of oxidation-reduction processes

Oxidation-reduction reactions have many far-reaching applications in our lives. Some of these applications are so common, that we take them for granted; others are not so obvious. The following are just a few examples of oxidation-reduction reactions. Bleaching Agents Photosynthesis Metabolism Nitrogen Fixation Combustion The Dry Cell Battery Electrochemistry Photo-oxidation (Photogray Æ Glasses) Corrosion

Combined gas law

P1V1/T1=P2V2/T2

Physical and chemical properties of acids

PHYSICAL PROPERTIES OF ACIDS It has a sour taste. It turns blue litmus to red. It turns methyl orange to red. Acids are electrolyte. Strong acids destroy fabric. Strong acids cause burn on skin. CHEMICAL PROPERTIES OF ACIDS NEUTRALIZATION An acid when reacts with a base, salt & water are produced. This reaction is called neutralization HCl + NaOH è NaCl + H2O HNO3 + NaOH è NaNO3 + H2O HCl + KOH è KCl + H2O REACTION WITH CARBONATES Acid and carbonates are combined to produce salt, water and carbon dioxide MgCO3 + 2HCl è MgCl2 + CO2 + H2O CaCO3 + 2HCl è CaCl2 + CO2 + H2O Na2CO3 + H2SO4 è Na2SO4 + CO2 + H2O CaCO3 + H2SO4 è CaSO4 + CO2 + H2O REACTION WITH BICARBONATES Acid and bicarbonates are combined to produce salt, water and carbon dioxide NaHCO3 + HCl è NaCl + CO2 + H2O REACTION WITH METAL With Zinc: Zn + 2HCl è ZnCl2 + H2 With Aluminum: 2Al + 6HCl è 2AlCl3 + 3H2 Reaction with iron oxide: 6HCl + Fe2O3 è 2FeCl3 + 3H2O

Physical and chemical properties of bases

PHYSICAL PROPERTIES OF BASE They have a bitter taste. They have slippery touch. They conduct electrically. It turns red litmus to blue. It turns colorless phenolphthalein to pink CHEMICAL PROPERTIES OF BASE REACTION WITH ACIDS: BASE + ACID è SALT + WATER KOH + HCl è KCl + H2O NaOH + HCl è NaCl + H2O REACTION WITH SALTS FeCl3 + 3NaOH è Fe(OH)3 + 3NaCl 2CrCl3 + 6NaOH è 2Cr(OH)3 + 6NaCl MgCl2 + 2NaOH è Mg(OH)2 + 2NaCl REACTION WITH METALS 2Al + 2NaOH + 2H2O è 2NaAlO2 + 3H2 Zn + NaOH + H2O è Na2ZnO2 + 2H2 Si + 2NaOH + H2O è Na2SiO3 + 2H2

Relationships among temp, pressure, volume, and number of molecules of an ideal gas

PV=nRT=NkT (P=pressure, V=volume, n=number of moles, R=universal gas constant [8.3145 J/mol K], T=absolute temp, N=# of molecules, k=Boltzman constant [1.38066 x 10-23 J/K = 8.617385 x 10-5 eV/K],

Periods in the periodic table

Periods: Rows which run horizontally. Labeled with a number: 1, 2, 3, 4, 5, 6, 7. These numbers indicate the total number of energy levels that any element in this period will have. For example, K (potassium) which is found in period 4, has 4 energy levels when diagrammed.

Thomson atomic model

Plum pudding model

Hydrophilic

Polar molecules are often called _____ for they , Having an affinity for water; readily absorbing or dissolving in water.

Physical and chemical properties of salts

Properties most salts have: -soluble in water -salt solutions are highly conductive -salts have a high melting point Some salts are liquid at room temperature (these are called ionic liquids), but most salts are solids.

Correlation of e⁻ config to chemical & physical properties

Rows in the periodic table are called periods. As one moves from left to right in a given period, the chemical properties of the elements slowly change. Columns in the periodic table are called groups. Elements in a given group in the periodic table share many similar chemical and physical properties.

Emission spectrum of H

RsubH=Rydberg constant = 1.097X10^-2 nm^-1

The mole

SI unit for the amount of substance present, 1 mole is 6.02 X 10²³ particles (Avogadro's number), also the link between the number of atoms in a substance and its mass in grams (# of atoms/grams)

Electron dot and structural formulas

Structural formulas have particular value in the study of organic chemistry. They show the arrangement of the atoms within the molecules as far as which atoms are bonded to which and whether single, double or triple bonds are used. The electron dot diagram shows how each atom has shared electrons to fill up its valence shell (or energy level).

Catalysts

Substances that reduce the activation energy of a chemical reaction., substance that speeds up a chemical reaction but is not used up itself or permanently changed

Chemical formulas

Tells what elements make up a compound and the ratios of the atoms of those elements. The @ symbol indicates an atom or molecule trapped inside a cage but not chemically bound to it. The formula (CH3)3CH implies a central carbon atom attached to one hydrogen atom and three CH3 groups.

Ionization energy

The amount of energy required to remove an electron from an atom.

In electroplating, which electrode is amde of the object to be plated? Of what substance is teh other electrode composed?

The electroplating process is facilitated by applying a negative charge onto the part object and immersing it into a salt solution of the metal to be deposited. The metallic ions of the salt solutions are charged positive by applying a positive charge to the solution and are drawn to the negatively charged part. When they reach the part, the negatively charge part will "reduce" the positively charged ions onto the metallic part.

How do the chemical characteristics of the elements in a period change as you move from left to right across the periodic table?

The physical and chemical properties of the elements in that period get increasingly opposite.

Stoichiometry

The relation between the quantities of substances that take part in a reaction or form a compound (typically a ratio of whole integers).

The effects of temperature and pressure on the solubility of a solute

The solubility of gas in water depends also on the temperature and pressure of the gas. Gases dissolve in water at high pressures and low temperatures.

Why is ammonia gas very soluble in water while O⁵ is only slightly soluble?

The water has two hydrogen atoms and one oxygen atom. The oxygen is more electro negative than hydrogen and hence the electrons are pulled towards the most electro negative element oxygen. This makes the oxygen to have partial negative charge and the hydrogen with partial positive charge. The same thing happens in the case of ammonia formation. The most electro negative element is nitrogen in ammonia compared to hydrogen. So the shared electrons are pulled towards the nitrogen and hence it possesses partial negative charge. The hydrogen possesses partial positive charge. This similar type of distribution of electrons in water and ammonia determines their polar nature.

Effect of temperature on chemical reaction rate

Usually, an increase in temperature is accompanied by an increase in the reaction rate. Temperature is a measure of the kinetic energy of a system, so higher temperature implies higher average kinetic energy of molecules and more collisions per unit time. Once the temperature reaches a certain point, some of the chemical species may be altered (e.g., denaturing of proteins) and the chemical reaction will slow or stop.

Valence electron behavior

Valence electrons are important in determining how the atom reacts chemically with other atoms. Atoms with a complete (closed) shell of valence electrons (corresponding to an electron configuration s2p6) tend to be chemically inert. Atoms with one or two valence electrons more than a closed shell are highly reactive because the extra electrons are easily removed to form positive ions. Atoms with one or two valence electrons fewer than a closed shell are also highly reactive because of a tendency either to gain the missing electrons and form negative ions, or to share electrons and form covalent bonds.

Charlie's Law

___ states that the volume of a fixed amount at constant temperature is inversely proportional to the gas pressure

Pascal

_____= one newton of force pushing on one square meter of area. (Unit measure for pressure)

Ionic Bond

a chemical bond in which one atom loses an electron to form a positive ion and the other atom gains to electron to form a negative ion

Covalent Bond

a chemical bond that involves sharing a pair of electrons between atoms in a molecule

Alkanes alkenes alkynes

a hydrocarbon containing only single covalent bonds Alkanes have the general chemical formula CⁿH₂n+₂ Hydrocarbons with one or more carbon-carbon double bonds a carbon compound with a carbon-carbon triple bond.

Decomposition chemical reactions

a reaction in which a single compound decomposes to two or more other substances. A general equation that describes a decomposition reaction is AB --> A + B where A and B can be elements or compounds. Most compounds can be broken down into simpler substances or decomposed. Often this can be done by heating the compound. For example the industrial preparation of lime (calcium oxide) involves the decomposition of calcium carbonate by heating it. CaCO3(s) ---> CaO(s) + CO2(g)

Combustion chemical reactions

a reaction in which a substance reacts with oxygen, usually with the rapid release of heat and the production of a flame. Organic compounds usually burn in the oxygen in air to produce carbon dioxide and if the compound contains hydrogen, another product will be water. For example butane burns in air as follows. 2 C4H10(g) + 13 O2(g) ---> 8 CO2(g) + 10 H2O(l)

Single replacement chemical reaction

a reaction in which an element reacts with a compound and replaces another element in the compound. A general equation that describes a single-replacement reaction is A + BC --> AB + C, where A and C are elements and BC and AB are compounds. The reaction in which copper displaces silver from an aqueous solution of silver nitrate is an example of a single-replacement reaction. Cu(s) + 2 AgNO3(aq) ---> Cu(NO3)2(aq) + 2 Ag(s)

Double replacement chemical reaction (precipitation and neutralization)

a reaction in which there is an exchange of positive ions between two compounds. These reactions generally take place between two ionic compounds in aqueous solution. A general equation that describes a double-replacement reaction is AB + CD --> AD + CB, where A and C are cations and B and D are anions. For a double-replacement reaction to occur, at least one of the products must be a gas or water, or a precipitate. Precipitation reactions are one type of double-replacement reaction. An example is AgNO3(aq) + NaCl(aq) ---> AgCl(s) + NaNO3(aq) This is what is called a molecular equation, which is a chemical equation in which the compounds are written as if they were molecular substances,even if they exist in solution as ions. Another type chemical equation is an ionic equation. The ionic equation shows soluble ionic compounds as individual ions in solution. Lets rewrite the equation above. Ag+(aq) + NO3-(aq) + Na+(aq) + Cl-(aq) ---> AgCl(s) + Na+(aq) + NO3-(aq) Next we cancel any ions that appear on both sides of the equation. Ag+(aq) + NO3-(aq) + Na+(aq) + Cl-(aq) ---> AgCl(s) + Na+(aq) + NO3-(aq) Remove the cancelled ions (called spectator ions) from the equation and we have Ag+(aq) + Cl-(aq) ---> AgCl(s) This is called a net ionic equation. A neutralization reaction is a reaction that occurs between an acid and a base with the formation of an ionic compound and water, if the reaction is in an aqueous solution. This is another type of double-replacement reaction. An example is HCl(aq) + NaOH(aq) ---> H2O(l) + NaCl(aq) The net ionic equation would be H+(aq) + OH-(aq) ---> H2O(l)

Combination chemical reactions

a reaction in which two substances combine to form a third. A general equation that describes a combination reaction is A + B --> AB. Again A and B can be either elements or compounds. Decomposition and combination reactions can be considered to be the reverse of each other. Under some conditions it is possible to change conditions and cause a decomposition reaction to become a combination reaction or vice versa. The reaction of calcium oxide with sulfur dioxide to form calcium sulfite is an example of a combination reaction. CaO(s) + SO2(g) ---> CaSO3(s)

Transmutations

a reaction which produces an atom with a different atomic number. Thus a different element is produced. Radioactive decays are one type of natural nuclear transmutation

Solvent

a substance in which another substance is dissolved

Nonelectrolytes

a substance that does not readily ionize when dissolved or melted and is a poor conductor of electricity

Characteristics & effects of various types of alpha radioactivity

alpha=He nucleus is produced; slow-moving; extremely dangerous in human body but harmless outside the body

Define isotopes

an isotope occurs when the number of neutrons is more or less than the number of protons

Examples of electroplating

applying metallic coating onto a part (chrome, nickel, gold, silver, etc.)

Atomic number v. atomic mass

atomic number=the number of protons also the identifying number of the element atomic mass=the mass of the protons plus the neutrons

Quantum mechanical atomic model

based on mathematics; used today to explain observations made on complex atoms; cloud model

Examples of voltaic cells

batteries and capacitors

Characteristics & effects of various types of beta radioactivity

beta=neutron changes to a proton; high-energy; ejected from nucleus; .9c; can penetrate human skin; negatively charged and have little mass

Aufbau principle

building up or construction; atoms are built up by progressly adding electrons to the most stable orbits (shells) 1s, 2s, 2p, 3s, 3p, 4s, 3d, 4p, 5s, 4d, 5p, 6s, 4f, 5d, 6p, 7s, 5f

Electrolytes

chemical substances that develop an electric charge and are able to conduct an electric current when placed in water; ions

Strong electrolytes

compounds that are completely ionize in water and easily conduct electricity; most salts are ______

Solvant

dissolving agent (ex- water)

Photoelectric effect

electrons are emitted from matter (metals and non-metallic solids, liquids or gases) as a consequence of their absorption of energy from electromagnetic radiation of very short wavelength, such as visible or ultraviolet radiation Light behaves as both waves and particles

Atomic structure location and number of electrons

electrons are located outside the nucleus, their exact location is difficult to pinpoint. Number of electrons is generally the same as protons. Atoms can gain or lose electrons becoming an ion (+/-).

What type of solvent would be needed to dissolve-- fat: fingernail polish: sugar: salt crystals:

fat: cyclohexane fingernail polish:nonpolar solvent such as acetone sugar and salt: both polar so water would work

Characteristics & effects of various types of gamma radioactivity

gamma similar to photons; very little mass and no charge; can penetrate centimeters of lead

Explain Rutherford's experiment

gold foil to explain the structure of atoms; downfall of plum pudding model; debunks theory that atoms are mostly space

Unsaturated

having a double or triple bond and capable of taking on elements or groups by direct chemical combination without the liberation of other elements or compounds

Characteristics of crystals

http://chemistry.about.com/cs/growingcrystals/a/aa011104a.htm

Stock and classical systems for indicating oxidation states on multivalent cations.

http://www.bcit.cc/132720868418987/lib/132720868418987/Chemical_Nomenclature_05.ppt

Factors affecting rate of dissolution

http://www.chemistrylecturenotes.com/html/factors_affecting_dissolution.html

pH scale

http://www.epa.gov/acidrain/education/site_students/images/phscale.gif

Covalent bond

is a form of chemical bonding that is characterized by the sharing of pairs of electrons between atoms

Ideal Gas Law

law that states the math relationship of pressure (P), volume (V), temperature (T), the gas constant (R), and the number of moles of a gas (n); PV=nRT.

Quantum numbers of electrons in various electron configurations

n=1,2,3,... (cannot be zero) principle number=size of orbital l=any integer between 0 and n-1 angular quantum number=shape of orbital m=any integer between -l and +l magnetic number=orientation in space of orbital

Atomic structure location and number of neutrons

neutrons are located in the nucleus; the number of neutrons can be calculated as the mass number minus the atomic number (mass=number with decimal)

The properties of the elements are periodic functions...

of their atomic mass.

Alcohols Carbohydrates

organic compounds containing hydroxyl groups (-OH) Organic compounds made of carbon, hydrogen, and oxygen atoms in the proportion of 1:2:1.

Fission

process in which the nucleus of an atom splits into smaller parts (lighter nuclei), often producing free neutrons and photons (in the form of gamma rays), and releasing a very large amount of energy, even by the energetic standards of radioactive decay

Atomic structure location & number of protons

protons are located in the nucleus; the number of protons can be found on the periodic table (atomic number=big number in upper left-hand corner)

Bohr atomic model

solar system model

Solutes

substances dissolved in a liquid

Chemical Bond

the attractive force that holds atoms or ions together. Give up individual properties

Correlation of e⁻ config to periodic table

the first two columns plus He are the s-block; the middle are the d-block; the last six columns fill the p-block; the bottom rows fill the f-block; blocks designate the shell orders

Energy of electrons in various configurations

the potential energy increases as the number of filled shells increases. This also accounts for "jumping" electrons from shell to shell

Gay-Lussac's Law

the pressure of a fixed mass of gas at constant volume varies directly with the Kelvin temperature

Fusion

the process by which two or more atomic nuclei join together, or "fuse", to form a single heavier nucleus

Hydration

the solution process with water as the solvent

Solute

the substance that is dissolved in a solution

Kinetic molecular theory

the theory that all matter is composed of particles (atoms and molecules) moving constantly in random directions

Metallic bond

where metals put all their electrons in a pool and they can move around (makes metal be able to bend and conduct elecrticity really well)

Carboxylic Acids Amines

₃compounds with carboxyl groups (-COOH) an organic compound with one or more amino groups (-NH₃)