Period+9+Chemistry

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** MgO lab Video by Angelo, Narciso, Jessica and Dustin: **
http://www.youtube.com/watch?v=U4ZFNMUPSxM

= = =MgO lab Video by Tatayana, Melissa, and Kassandra:= http://www.youtube.com/watch?v=8CtiW-uT2hw

=MgO Lab Video by Allison, Joseph, Greg, Aurora= http://www.youtube.com/watch?v=Oq7MgQ0UjKk It's on youtube. :D = = =MgO Lab Daron, Angela, Vy, Diego= http://www.youtube.com/watch?v=07pBZ6qEfdw

=MgO Lab Video by Anton,Sid,Justin,Sean= media type="youtube" key="eB55J2sjqrk?fs=1" height="505" width="640" = = = = =MgO Video= http://www.youtube.com/watch?v=IsgqD1JQxzU Percival Perlas, Violet Albanes, Kim Ly, Alston Pacheco


 * MgO Video**

media type="youtube" key="WA4MixruyxQ?fs=1" height="385" width="640" Kelsen Adeni, Devan Bevilacqua, Scott Lowder, Chris Torres

= = =Period 9 Chemistry Page =

**__Measurement Topic - class study guide__**

**__ Vocab __** **__ Lesson 3:1 __**

Measurements- A quantity that has both a number and a unit.

Scientific Notation- a given number is written as the product of two numbers: A coefficient and 10 raised to a power

Accuracy- A measure of how close a measurement comes to the actual or true value of whatever is measured.

Precision- A measure of how close a series of measurements are to one another.

Accepted Value- Correct value based on reliable references.

Experimental Value- The Value measured in a lab.

Error- The difference between the experimental value and the accepted value

Percent Error- The absolute value of the error divided by the accepted value, multiplied by 100%

Significant Figures- A measurement that all of the digits are known, plus a last digit that is estimated

** Lesson 3:2 **

International System of Units- a revised version of the metric system.

Meter- the basic unit of length, or linear measurement

Liter- the volume of a cube measuring 10 centimeters on each edge. It is the common unprefixed unit of volume in the metric system.

Kilogram (kg)- the basic SI unit of mass

Weight- a force that measures the pull on a given mass by gravity.

Temperature- a measure of how hot or cold an object is.

Celsius scale- sets the freezing point of water at 0 C and the boiling point of water at 100C

Kelvin scale- the freezing point of water is 273.15

Absolute zero- the zero point on the Kelvin temperature scale equivalent to -275.15 C (3.2)

Energy- the capacity to do work or to produce heat.

joile (j)- the SI unit of energy.

calorie- the quantity of heat that raises the temperature of 1 g of pure water by 1 C.

Vocab 3:3 Conversion factor- a ratio of equivalent measurements

Dimensional analysis - method to analyze and solve problems using the units (dimensions) of the measurements

**__Sig Fig Rules:__**

(By: Violeta Albanes, Kim Ly, Alston Pacheco, and Percival Perlas ﻿1) Any non-zero digits are significant. (For example! 12304. 1, 2, 3, and 4 ARE **significan**t, 0 is **not**.)
 * The FIVE MAIN RULES: **

2) Any zeros between numbers are significant. (For example! 305 = 0 IS significant.)

3) Zeros to the left of the **first** non-zero digit are NOT significant. (Sample: __0__34 = 0 is NOT significant.)

4) Final zeros **after** the decimal are significant. (Just like 4.50 = 0 IS significant.)

5) Zeros to the right of the last non zero digit **without** a decimal point NOT significant. (Such as: 520 = 0 is NOT significant.)

-If a **decimal point** is present, do NOT count zeros on the "Pacific" (left) side.
 * Other IMPORTANT RULES: **

-If there is **no decimal point** do NOT count zeros on the "Atlantic" (right) side.

-Every **other digit** is significant.

===**//__Table B: Significant Figures Calculations! __//**=== By: Anton, Justin, Sid, Sean

-When carrying out multiplication, your number must be written to the lowest number of significant figures that were in the problem: For example: 3g x 295 g => 1sf x 3 sf => Answer must be written to 1 sig. fig!

-When adding or subtracting, the answer must be given to the lowest number of places past the decimal that were in the problem! -For example: 23.6 mL - 16.1218 mL => 1dp - 4dp => Answer must be given to 1 decimal place!

-So....what about multiplication/division AND subtraction/addition? Give your answer to the lowest number of significant numbers that were in the problem!

-For example: 5.46 mg x 3.2 mg + 1.59 mg => 19 mg (2 sig. figs.)

Good luck on your Test !!! Some Metric units are available by clicking the link here

__** Precision and Accuracy: **__ Tatyana Lark, Melissa Palanca, Kassandra Mangoba, Brenden Espanola  In Science, we want measurements to be both accurate and precise  -Accuracy is a measure of rightness -Precision is a measure of exactness
 * Capable of providing a correct reading or measurement
 * Refers to how closely a measured value agrees with the correct value
 * A measurement is accurate if it correctly reflects the size of the thing being measured
 * Repeatable, reliable, getting the same measurement each time
 * Refers to how closely individual measurements agree with each other

Scientific Notation **Table D**
By: Darshan, Mark, Milton, and Emerald Scientific Notation is a way of expressing extremely large or small numbers using coefficients and powers of 10.

A practical way to use this technique is when you are doing a laboratory activity when working with miniscule or big numbers.

Scientific notation is expressed in the basic form **a x 10^n.**

The steps to express a number in scientific notation are the following:

1) Decide whether you move left or right depending on the location of the non-zero numbers. 2) Count the number of places you move the decimal point until the decimal point reaches between the first two numbers that are non-zero. 3) Determine the coefficient (a) 4) From Step 1, if you moved left, express the number of times you moved as a number, n, with a positive number. Or if you moved the decimal point right, express it as the negative number, -n. 5) Express the number given in the form a x 10^n.

**Example:**

0.000000000464755

Step 1: Decide whether you move left or right depending on the location of the non-zero numbers- in this case, you move to the **right**.

Step 2: Count the number of places you move the decimal point until the decimal point reaches between the first two numbers that are non-zero. In this example, we move **10** places to the **right**.

Step 3: Determine the coefficient (a). **4.64755**

Step 4: From Step 1, if you moved left, express the number of times you moved as a number, n, with a positive number. Or if you moved the decimal point right, express it as the negative number, -n.

Therefore, the exponent will be **-10** because we moved 10 places to the **right.**

Step 5: Express the number given in the form a x 10^n. PLEASE DON'T DELETE THIS. =__ SI Units: The International System of Units __= By Angelo Acosta, Narciso Bernardo, Jessica Matias & Dustin Vo
 * 4.64755 x 10^-10**   **Otherwise if we had the number:**   464,755  then we would have to find the decimal point shown here as 464,755 **.**   Ok, so now what we can do is find out how many places we have to move to the **left**.  In this case we move 5 places to the left to produce the number **4.64755**  Then we add the power of 10 we used to complete this scientific notation figure.  The final answer is 4.64755 X 10^5  Good luck on the test!

The standards of measurement used in science are those of the metric system because of its simplicity and ease of use. The International System of Units is a revised version of the metric system. There are **7 SI base units**, from which all other SI units can be derived. The 5 **most commonly used by chemists** are the meter, kilogram, kelvin, second, and mole.

The seven SI base units are:
 * **Meter** (m) : unit of length
 * ** Kilogram ** (kg) **:** unit of mass
 * ** Kelvin ** (K)** : ** unit of temperature
 * ** Second ** (s)** : ** unit of time
 * ** Mole ** (mol)** : ** amount of substance
 * ** Candela ** (cd)** : ** luminous intensity
 * **Ampere** (A) : electric current

Metric Prefixes:
 * ** mega ** (M) - 1 million times larger than the unit it precedes; 10^6 (ten to the power of six)
 * ** kilo **(k) - 1000 times larger than the unit it precedes; 10^3
 * ** deci ** (d) - 10 times smaller than the unit it precedes; 10^ -1
 * ** centi ** (c) - 100 times smaller than the unit it precedes; 10^ -2
 * ** milli ** (m) - 1000 times smaller;10^ -3
 * ** micro **(µ) - 1 million times smaller than the unit it precedes; 10^ -6
 * **nano ** (n) - 1000 million times smaller than the unit it precedes; 10^ -9
 * **pico **(p) - 1 trillion times smaller than the unit it precedes; 10^ -12

-length: centimeter, meter, kilometer -volume: liter, milliliter, cubic centimeter, microliter -mass: kilogram, gram, milligram, microgram -temperature: Celsius, kelvin -energy: joule, calorie
 * __ Common metric units of: __**

The **difference** between **weight and mass** is that:
 * 1) Weight is the force that measures the pull on a given mass by gravity.
 * 2) Mass is a measure of the quantity of matter.
 * 3) Weight can change depending on it's location, but mass remains the same regardless of its location.
 * 4) Objects can become weightless, but not massless.

By Devan Bevilacqua and Scott Lowder
Dimensional analysis is a way to analyze and solve problems using the units, or dimensions, of the measurements. This method provides you with an alternative approach to problem solving.

Ex 1: How many seconds are in a workday that lasts exactly 8 hours?

7 hr X __60 min__ X __60 seconds__ = 25, 200 seconds (2.5200 X 104 seconds) 1 hr 1 min

Step 1: Figure out what unit you want your end result to be Step 2: Decide what conversion factors (ratio of equivalent measurements) are needed to complete the problem Step 3: Set up the problem (as shown above) Step 4: Solve Step 5: Convert to appropriate number of significant figures

Problems in which a measurement with one unit is converted to an equivalent measurement with another unit are easily solved using dimensional analysis.

Ex. 2: Express 4.6 mg in grams

4.6 mg X __1 gram__ = 0.0046 grams (4.6 X 10-3 grams) 1000 mg

Multistep Problem:

Ex 3: What is 0.053 cm in micrometers?

5.3 X 10-2 cm X __1 meters__ X __106 micrometer__ = 5.3 X 102 micrometers 102 cm 1 meter