Lab Equipment Overview. beakers Erlenmeyer flask Graduated cylinders Test tube.
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Transcript of Lab Equipment Overview. beakers Erlenmeyer flask Graduated cylinders Test tube.
Lab Equipment Overview
beakers Erlenmeyer flask
Graduated cylinders Test tube
funnel wash bottle test tube brush
scoopula microspatula 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
crucible evaporating dish mortar and pestle
watch glass thermometer rubber stoppers
Bell RingerWrite 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?
ChemistryThe 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
ChemistryChemistry 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))
ObservationsVisual 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
ExampleInference
◦“The material looks like grass.”
Observation◦“The material is
green.”
Candle Mini-Lab
Make observations about the following situations:
1. Lights on, not lit2. Predict what will happen when we
light the candle3. Lights on, light candle4. Lights off, candle lit5. Lights off, blow out candle
What is Matter???
Phases of MatterIdentify 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
ParticlesSubmicroscopic particles are able to vibrate about their fixed positions.
What happens when we add heat???◦Vibrations increase◦At a certain temp they have enough energy
to disrupt the fixed positions (changing the phase)
◦Adding heat: Solid Liquid Gas
What is Matter???
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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
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 increasesWhat 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?
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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:
Mass Before Mix (g) Mass After Mix (g)Container & Water Salt & Dish Beaker & Water & Salt
Mass of Container:______ Mass of Dish:_________ Mass of Container:____________
Mass of Water:_______ Mass of Salt:__________ Mass of Mixture:___________
Total Mass Before Mix Total Mass After Mix
Mass of Water + Salt = __________ Mass of Water + Salt = ________
Calculate Change in Mass (Δm = mf - mi)
Δm =____________________
Lab Group # Change in Mass (Δm)
1
2
3
4
5
6
7
8
9
10
11
12
13
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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 Mix Total Mass After Mix
Mass of Water + Alka Seltzer =
__________
Mass of Water + Alka Seltzer
= ________
Mass of Water + Alka Seltzer
= ________
Calculate Change in Mass
(Δm = mf - mi)
Δm (closed system)
=_______________
Δm (open system)
=_______________
Lab Group # Change in Mass (Δm)
1
2
3
4
5
6
7
8
9
10
11
12
13
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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.
□ http://www.bbc.co.uk/schools/scienceclips/ages/10_11/rev_irrev_changes_fs.shtml
Example Chemical Reaction
□Before
During (fire,smoke)
□After change
ChemicalChemical 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
