Chemistry Mrs. Welke

Math survey Syllabus Check your last math class List the grade of that class List the grade of 9th grade Physics (Fode’s class) Syllabus Calculator needed No food or drinks No phones, etc. Grading Labs Safety Agreement

Chemistry: An Introduction Unit 1 Chemistry Mrs. Welke Chemistry: An Introduction

Observations in Science Qualitative Observations made by using descriptive words to explain. Quantitative Observations made by using numbers and/or measurements to describe.

Candle Lab Practice your observation skills Make 10 qualitative observations Be sure to write each partners name on the sheet you hand in.

Pricing Equipment Use chrom book Find each piece of equipment listed Use the web site of your choice flinnsci.com is great Find each piece of equipment listed You choose the quality of the style you choose No plastic (except funnels or test tube racks) List the price on one of each item If they come as a quantity, divide to determine the price of one! Total the equipment

Measuring liquids is done by reading the volume at the bottom of the meniscus.

Electronic scales When using the scales: Push on/off Wait until 0.00 g appears Place massing paper on the scale Push zero to return the scale to 0.00 g and ignore the mass of the paper

Lab Safety Perform labs when teacher present Read lab carefully Know the location of safety equipment Wear safety goggles Long hair up & proper clothing Keep lab counter clean Check all chemical labs multiple times Never taste lab materials Wash hands before touching eyes!

Lab Safety When instructed to smell, fan vapors Never look down into a test tube Report all lab accidents! Chemical splashes flush with water 15 minutes Minor burns place under cold water Dispose of chemicals as instructed for each lab Return equipment & chemicals to designated locations Clean up! Turn off gas, Turn off water, Clean counter, Clean sink, Place key on board Wash hand before leaving

Safety Agreement You need to read & sign Your parent needs to read & sign List parent contact information Due back to me before Wed. 9/13

Scientific Method Observation made that makes you wonder Formulate a hypothesis, an educated guess Design and conduct an experiment to gather data through observations Organize the data to look for regularities (Scientific laws are formulated, which are a summary of what is going on) Wonder why the regularities exist (Scientific theories are developed, they are an explanation of what is going on) Communicate findings to others

UNIT 1 Matter

Matter: It has mass & takes up space. Composed of ATOMS There are over 100 different types of atoms Substance with only 1 type of atom is an ELEMENT Substance made by bonding atoms together in a specific way is a COMPOUND Smallest unit of a compound, made of 2 or more atoms bonded together is a MOLECULE If made of 2 atoms of the same element, it is called a diatomic molecule (H2 O2 N2 F2 Cl2 Br2 I2 )

Signs of a Chemical Reaction Color change Change in temperature Formation of a gas (look for bubbles) Formation of a precipitate (precipitate is a solid formed when mixing 2 liquids together)

Observation & Experiment Wear safety glasses Look for signs of a chemical change Conduct each of the 7 individual experiments (bmeans to use that chemical) Write down qualitative observations All chemicals can go down the drain

Physical properties – Chemical properties The ability of a substance to undergo a specific chemical change. Example: Wood burning to give off gases, heat, and ashes. A characteristic of a substance that can be observed or measured without changing the substance’s composition. Example: odor, color, volume, state, density, melting point, boiling point

Physical Change - Chemical Change A change in the form of a substance, but not in its chemical nature; chemical bonds are not broken in a physical change. Ex: Solid water (ice) melting to form liquid water Ex: sugar dissolving in water The change of substances into other substances through a reorganization of the atoms; a chemical reaction. Bonds are broken and formed. Ex: An explosion

Fractional Distillation: The process of separating the components of a liquid mixture that depends of differences in the boiling points (vaporization temperatures) of the components.

Petroleum has many components that humans use Petroleum has many components that humans use. Each type of molecule will boil off at different temperatures, allowing for the separation of them. The smaller the molecule, the lower the boiling point.

Filtration: A method for separating the components of a mixture containing a solid and a liquid. Both distillation and filtration use physical properties to separate components that are mixed, but not chemically combined.

Chemical classifications Technical: chemicals of purity adequate for commercial use Pure or Practical: chemicals suitable for most laboratory requirements Laboratory Grade: Chemicals conforming in purity to the US Pharmacopeia. Safe for human use unless label indicates otherwise. ACS: Chemicals which meet the requirements of the American Chemical Society. Reagent Grade: Highly purified chemicals suitable for research. Least Pure Most Pure

Globally Harmonized System of Classification and Labeling of Chemicals These will not be on exam!

Learn some of the Names of Elements – Word Find Find the full names of the elements The word find contains the names of the first 103 elements Find each name only once Find 50 names

Review b and c See equipment It is the middle quality chemical. It conforms to the purity of the US Pharmacopeia. Always Clean up after yourself! Scientific Law Methane gas by the wheel on the bottom, Atmospheric air by the barrel openings. Smallest unit of a compound, made of 2 or more atoms bonded together. White, solid, etc. Color change, temperature change, gas formation, precipitate formation.

Pure composition Variable composition

Homogeneous mixture Solutions Solid solution - Alloys Mixture of metals Gaseous solution Liquid solution