Lab Equipment Overview

beakers Erlenmeyer flask Graduated cylinders Test tube

funnel wash bottle test tube brush scoopulamicrospatula glass stirring rod

test tube holder Beaker tongs Crucible tongs wire gauze

ring clamp ring stand test tube clamp bunsen burner clay triangle test tube holder

crucibleevaporating dishmortar and pestle watch glass thermometer rubber stoppers

Bell Ringer Write down 5 things that come to mind when you hear the word chemistry. Write down 2 “jobs” that someone could have that uses chemistry.

What is Chemistry?

Chemistry The study of the composition and structure of matter (anything that has mass) and the chemical reactions by which substances are changed into other substances. Where did chemistry begin??? ◦ 100,000 years ago (Earth Dwellers discovered fire) ◦ Egyptian  used wine making (chemical fermentation process)  Metals  Dyes, glass, pottery, embalming fluids

Chemistry Chemistry has 5 major divisions ◦ Physical chemistry  (uses theories of physics such as thermodynamics) ◦ Analytical chemistry  (identifies what substances are present in materials) ◦ Organic chemistry  (study of compounds that contain carbon) ◦ Inorganic chemistry  (study of non-living compounds) ◦ Biochemistry  (uses theories of biology and living organisms (respiration, digestion, photosynthesis))

Observations Visual Information ◦ Colors, movement, light intensity, etc.. Audible Information ◦ Sounds, bubbling, fizzing, etc… Olfactory Information ◦ Smells, aromas, etc… Tactile Information ◦ Texture, hardness, temperature, etc…. Inferences are hypotheses based on observations Inferences

Example Inference ◦ “The material looks like grass.” Observation ◦ “The material is green.”

Candle Mini-Lab Make observations about the following situations: 1. Lights on, not lit 2. Predict what will happen when we light the candle 3. Lights on, light candle 4. Lights off, candle lit 5. Lights off, blow out candle

What is Matter???

Phases of Matter Identify which box represents a solid, liquid or gas. Solid -Holds Shape -Fixed Volume Liquid - Shape of container -Fixed Volume Gas -Shape of Container -Volume of Container

Particles Submicroscopic particles are able to vibrate about their fixed positions. What happens when we add heat??? ◦V◦V ibrations increase ◦A◦A t a certain temp they have enough energy to disrupt the fixed positions (changing the phase) ◦A◦A dding heat: SSolid  Liquid  Gas

What is Matter???

Systems System – Well-defined group of objects or materials Open System – System that continuously interacts with its environment Closed System – System in which no mass may be transferred outside or inside the system boundaries 18

MASS Is mass a reliable measurement? Can we be certain of it? Is mass more reliable than volume? Does it change ? Lets find out?

Water freezes? What happens to the volume of water as it freezes into ice? It expands. Volume increases What if ice melts, does it’s volume decrease? Does its MASS increase or decrease?

When salt dissolves in water, the volume decreases! Why? Where does the water go?

What happens to the mass of our system when we mix substances?

Salt & Water Lab Purpose: to determine what happens to the mass of the system when salt is added to water. Hypothesis: I predict that the mass will ________ Procedure: 23

Mass Before Mix (g)Mass After Mix (g) Container & WaterSalt & DishBeaker & Water & Salt Mass of Container:______Mass of Dish:_________Mass of Container:____________ Mass of Water:_______Mass of Salt:__________Mass of Mixture:___________ Total Mass Before MixTotal Mass After Mix Mass of Water + Salt = __________Mass of Water + Salt = ________ Calculate Change in Mass (Δm = m f - m i ) Δm =____________________

Lab Group #Change in Mass (Δm)

Mass Before Mix (g) Mass After Mix (g) With Balloon On (Closed System) Mass After Mix (g) With Balloon Off (Open System) Container & Water Alka Seltzer & Balloon Container, Water, Alka Seltzer, & balloon Container, Water, Alka Seltzer Mass of Container:______ Mass of balloon:_____ Mass of Container & balloon: ____________ Mass of Container:____________ Mass of Water:_______ Mass of Alka Seltzer:_____ Mass of Mixture:___________ Mass of Mixture:_____________ Total Mass Before MixTotal Mass After Mix Mass of Water + Alka Seltzer = __________ Mass of Water + Alka Seltzer = ________ Calculate Change in Mass (Δm = m f - m i ) Δm (closed system) =_______________ Δm (open system) =_______________

Lab Group #Change in Mass (Δm)

Physical & Chemical Changes

Physical Change □A change in the physical property of a substance □The chemical properties remain the same □Ex: ice to water, carving wood…

Any characteristic that can be observed or measured is a physical property. Length can be measured.

Physical Physical Properties □ Def: Properties that can be seen without changing the identity of the substance. □Ex: color, shape, hardness, odor, density, dissolvability, mass, weight, volume, texture □ Def: changes from one phase to another (solid, liquid, gas), without changing the substance □Ex: □Chopping, slicing, sawing, grinding, dissolving □Melting/ Freezing □Vaporizing (Boiling) □Condensation □Sublimation □Evaporation Physical Changes

Chemical Change □A substance is transformed into a new substance □Involves a chemical reaction □Ex. Iron rusting (with oxygen) to form iron oxide, chemical explosions, burning of wood

Signs of a Chemical Change □Signs of a chemical change include the production of bubbles, heat, light, smoke, sounds or color changes. □Chemical changes are not reversible using physical means. □

Example Chemical Reaction □Before During (fire,smoke) □After change

Chemical Chemical Properties □Def: Properties that describe how a substance changes into a new substance □Ex: flammability (burning) Chemical Changes □Def: The process by which a substance changes to a new substance □Ex: □Combustion (burning) □Respiration □Digestion □Leaves changing color □Rusting □Photosynthesis □Baking/cooking □Gasoline burning □Alka seltzer in water reacting