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 * -Joe Jennings, Editor **

=**Problem Solving in Chemsistry**=

Skills Used in Solving Problems
Problem solving skills are useful in everyday life.

There are many tools that can be helpful in the process of problem solving. There are data tables, graphs, and many other types of visuals that can be very useful.

Similar skills are used in solving Chemistry word problems as problem solving in everyday life, like shopping or cooking.

Solving Numeric Problems
There is a three- step problem solving strategy for solving problems, especially math problems, in Chemistry. The steps in this strategy are analyze, calculate, and evaluate.

Analyze: - The part of analyzing is to figure out where you are starting from, or identify what parts of the problem are already known and what is unknown. - Then, you must make a plan as to how you will arrive at the answer. Drawing a diagram or a table may be helpful for this step.

Calculate: - After you have finished planning, you should use the plan you have come up with to start doing the calculations. - This step may require converting measurements or rearranging equations.

Evaluate: - Lastly, after you have calculated your answer, you should look back and see if it makes sense. - Check to mak sure the answer has correct labels and correct number of significant figures.


 * __3.2: The International System of Units, Pages 76 – 79__**
 * Written By: Jonathan Bailey (Co-Editor) (Pages 76-79) **
 * Also Written By: Sean Lydon (Pages 73-76) **
 * Metric Units of Mass **
 * **Unit** || **Relationship** || **Example** ||
 * Kilogram (kg) (base unit) || 1kg = 1000g || Small textbook = 1kg ||
 * Gram (g) || 1g = 0.001kg || Dollar Bill = 1g ||
 * Milligram (mg) || 1000mg = 1g || Ten grains of salt = 1mg ||
 * Microgram (ug) || 1,000,000ug = 1g || Particle of baking powder = 1ug ||
 * Microgram (ug) || 1,000,000ug = 1g || Particle of baking powder = 1ug ||

The mass of an object is measured in comparison to a standard mass of 1 kilogram (kg), the basic unit of mass. Almost all substances expand with the increase of heat, and contract with the increase of cold. Thermometers have liquid inside them that expand and contract more than the volume of the glass containing them. Several different temperature scales have been devised. The Celsius scale is named after the Swedish astronomer Anders Celsius (1701 – 1744) The Kelvin scale was named after a Scottish physicist and mathematician, Lord Kelvin (1824 – 1907) The change of one degree Celsius is the equivalent to one Kelvin. Normal human body temperature is 37 degrees Celsius. What is the temperature in kelvins?
 * A kilogram was originally defined as the mass of 1 Liter (L) of liquid water at 4 Degrees Celsius.
 * You can use a platform balance to measure the mass of an object.
 * Analytical Balance**: Used to measure objects less than 100g and can determine mass to the nearest 0.1mg.
 * Weight**: A force that measures the pull given on mass by gravity.
 * Different than mass, because mass is a measure of quantity of matter.
 * The weight of an object can change with location (Being on the moon you weigh less)
 * Mass remains constant regardless of location (You still have the same amount of matter everywhere).
 * You can become weightless, but not massless.
 * __ Units of Temperature __**
 * Temperature**: A measure of how hot or cold an object is.
 * Temperature determines the direction of heat transfer in an object.
 * Heat moves from the places of highest temperature to the lowest places of temperature.
 * An exception to this is water.
 * This causes the column of liquid in a thermometer to rise and fall depending on how hot or cold something is.
 * Scientists commonly use two equivalent units of temperature, the degree Celsius and the Kelvin.
 * Uses two determined temperatures as reference
 * The freezing point of water ( 0 degrees Celsius)
 * The boiling point of water ( 100 degrees Celsius)
 * The freezing point of water is 273.15 kelvins (K)
 * Boiling point is 373.15 K.
 * Degree sign is not used with Kelvin scale.
 * Absolute Zero**: 0 Kelvins on the Kelvin scale, -273.15 degrees Celsius.
 * __ How to Convert Between Temperature Scales __**
 * Sample Problem: **

Known: Unknown: Use the known value and the equation (K = degrees Celsius + 273) to calculate the temperature in Kelvins. Substitute the known value for the Celsius temperature into the equation and solve. K = degrees Celsius + 273 37 + 273 = 310 K
 * 1) **List the known and unknown**.
 * Temperature in Celsius = 37 degrees
 * Temperature in K = ? K
 * 1) **Solve for the unknown**.

You should expect a temperature within this range, since the freezing point of water is 273 K and the boiling point is 373 K; normal body temperature is between these two values.
 * 1) **Does this result make sense?**

Like any other quantity, energy is able to be measured. Joule: The SI unit of energy, named after English physicist James Prescott Joule (1818 – 1889) One calorie (cal) is the quantity of heat that raises the temperature of 1g of pure water by 1 Degree Celsius. -Scientific quantities can be expressed in many different ways, but still mean the same thing  - example: 1 meter=10 decimeters=100 centimeters=1000 millimeters -When two measurements are equal, the ratio of the two measurements equals 1  - they can cancel out
 * __ Units of Energy __**
 * Common units of energy are the joule (J) and the calorie (cal).
 * 1 Joule = 0.2390 cal
 * 1 cal = 4.184 Joules
 * 3 ****.3 Conversion Problems Pages 80-87 **
 * Coediter: Maddie Harmon (pages 80-83) **
 * Marie Wachter ****(Marie has pages 84-87) **
 * __Conversion Factors__ **



-A conversion factor is a ratio of equvalent measurements  - When converting measurements, the measurement on the numerator and the measurement on the denominator are equivalent.

-Conversion factors are very useful in solving problems where one measurement must be converted to another measurement  - Example: How many centimeters are in 5 meters?  - 5 meters = 1oo centimeters/1 meter = 500 centimeters -When a measurement is multiplied by a conversion factor, the numerical value is generally changed, but the actual size of the quantity stays the same <span style="color: #d813ac; font-family: Georgia,serif;"> - 5 meters and 500 centimeters are numerically changed, but quantities are equal

<span style="color: #d813ac; font-family: Georgia,serif;">media type="youtube" key="XKCZn5MLKvk" height="315" width="420"

<span style="color: #d813ac; font-family: Georgia,serif;">-Dimensional Analysis is a way to analyze and solve problems wiht units, measurements, or dimensions. <span style="color: #d813ac; font-family: Georgia,serif;">-It provides you with an alternate way to solve problems (other than algebra) <span style="color: #d813ac; font-family: Georgia,serif;">- Steps to solving problems by dimensional analysis <span style="color: #d813ac; font-family: Georgia,serif;"> 1. Identify the destination, including units. <span style="color: #d813ac; font-family: Georgia,serif;"> 2. Choose a starting point <span style="color: #d813ac; font-family: Georgia,serif;"><range type="comment" id="218602"> -this starting point is usually given <span style="color: #d813ac; font-family: Georgia,serif;"> 3. List the connecting conversion factors <span style="color: #d813ac; font-family: Georgia,serif;"> -make sure they will cancel out <span style="color: #d813ac; font-family: Georgia,serif;"> 4. Multiply the starting measurement by conversion factors <span style="color: #d813ac; font-family: Georgia,serif;"> 5. Evaluate: Does the answer make sense?
 * <span style="color: #d813ac; font-family: Georgia,serif;">__Dimensional Analysis__ **

<span style="color: #d813ac; font-family: Georgia,serif;">-This video shows an example problem, using dimensional analysis <span style="color: #d813ac; font-family: Georgia,serif;">media type="youtube" key="UOLfrQWKCnM" height="315" width="560"

Chapter 1.2-Chemistry Far and Wide (Pages 12-19) Co-editor: Darby Barrett (pages 15-19) Brittany Chlebek (pages 12-14)

Materials: Energy: Medicine and Biotechnology: Biotechnology YouTube Video: [|Biotechnolgy]
 * Chemists design materials to fit specific needs
 * they usually use nature, to search for their inspiration
 * There are 2 ways to look at the world - macroscopic and microscopic views
 * macroscopic world - the world of objects that are large enough to see with the unaided eye
 * microscopic world - the world of objects that can be seen only under magnification
 * Energy is necessary to meet the needs of a modern society - used to heat buildings, manufacture goods, etc.
 * The demands of energy continue to increase, as the population of people on Earth increases
 * There are 2 ways t meet the demand for energy - conserve energy resources and find ways to produce more energy
 * Chemists play an essential role in finding ways to conserve energy, produce energy, and store energy
 * Conservation:
 * The easiest way to conserve energy is insulation - which acts as a barrier to heat flow from the inside to the outside of a house or from the outside to the inside of a freezer
 * SEAgel is the most exciting modern insulation - it is a foam made from seaweed
 * Production:
 * Fossil fuels are formed from the remains of ancient plants and animals
 * Fossil fuels are limited, however
 * Scientists are looking for ways to obtain fuel from plants
 * Storage:
 * Batteries use chemicals to store energy that will be released as electric current when the batteries are used
 * Batteries vary in size, levels of power, and time for operation
 * Cordless tools were first developed by NASA
 * Chemistry supplies the medicines, materials, and technology that doctors use to treat their patients.
 * The overall goal of biochemists is to understand the structure of matter found in the human body and the chemical changes that occur in cells
 * Medicines:
 * There are over 2,000 prescription drugs for many different treatments/conditions
 * OTC (over the counter) drugs can be sold without a prescription
 * Knowledge of the structure and function of target chemicals helps a chemist to design a safe and effective drug
 * Materials:
 * Chemists sometimes have to repair or replace body parts
 * Artificial hips & knees, plastic tubes for diseased arteries, etc.
 * Biotechnology:
 * Genes, segments of DNA, store the information that controls changes that take place in cells
 * Biotechnology applies science to the production of biological products or processes. When genes from humans are insterted into beacteria, the bacteria acts as factories because they produce chemicals of importance to humans
 * Scientists expect to use gene therapy to treat some diseases in the future