warm up: p12 what is the difference between an element compound and mixture? compare and contrast...
TRANSCRIPT
Warm Up: p12
What is the difference between an element compound and mixture?
Compare and Contrast reactants and products.
Date Session # Activity Page #
11/12-13 6 How to Balance a Chemical Equation 9
11/16-17 7 Reaction Rates 10
Reaction Rate Lab 11
11/18-19 8 Sugar Water Unit Review 12
Study for the testECM, Conservation of Mass, Reaction Rates test Monday 11/23Review session Thursday 8am and after school
8.P.1 Understand the physical properties of matter and changes that occur when matter interacts in an open or closed container8.P.1.4 Explain how the idea of atoms and a balanced chemical equation support the law of conservation of mass
TLW analyze various text, then explain how these texts explain the law of conservation of mass/matter.
What is going on during a chemical reaction???
Collisions between molecules or individual atoms (specifically, the valence electrons of those materials) may lead to a chemical reaction.
The reaction rate is the speed with which a reaction occurs. If the rate of the reaction is slow, that means molecules are combining/colliding at a slower speed than a reaction that occurs at a higher rate.
If you increases the number of successful collisions in a system, more combinations of molecules can occur. The reaction will go faster………the rate of the reaction will increase.
You will need a timer…Glue data table to p 11
Variable Time to Complete Reaction
CONTROL (room temp tap water)
Flubber,No……Flubber,YesFlubber is a polymer. Polymers are LARGE molecules, made of identical molecules that are connected by chemical bonds. Polymers can be naturally occurring or manmade. Manmade polymers are materials like nylon and polyester. You have natural polymers in your body. These polymers are the large proteins that make up microtubules and microfilaments that are structural components within your cells.
Flubber, NoDescribe the glue and water solution in your data table
Reactants Observations
Glue + Water
Glue + Water + Borax Solution
Flubber, No• White glue is made of molecules of vinyl acetate.
• These molecules can make very long polymers (polyvinyl acetate) but they cannot bond on their own. It requires too much energy and they have to be lined up correctly.
• They need help getting the reaction started…they need a catalyst.
Our catalyst for this reactionis Borax (Na2B4O7)
Flubber, Yes1. Add the borax solution to your glue & water
solution. Stir with the craft stick.2. Describe the result in your data tableThe borax DOES NOT BOND with the vinyl acetate
molecules….it just helps bonds them with each other.
It is not part of the reaction….it is still in the leftover liquid in your cup….we could re-use it.
Why the difference betweenB1 + C and B2 + C?
Discuss with your group….you must be able to explain how the variable caused the difference in reaction rates.
Be prepared to share
Why the difference betweenB1 + C and B2 + C?
By the way…..
Solution B1 & B2 contain the same chemicals
Everyone got the same solution C
http://ed.ted.com/lessons/how-to-speed-up-chemical-reactions-and-get-a-date
Reaction Ratesspeed of reaction/number of collisions
affected by
Temperature Concentration Surface Area Catalyst change speed increase # of particles, expose more particles agent to lower energy & or reduce container size to each other orient particles
hot increases rate increased conc. Larger surface area speeds up or starts Cold decreases rate increases rate increases rate reaction w/o being consumed..no e- bonds
Lab: hot tablet iodine clock: B2 crushed tablet flubber: w/o borax reacted faster had larger iodine reacted faster the reaction didn’t conc. so it reacted occur faster
Reaction Ratesspeed of reaction/number of collisions
affected by
Temperature concentration surface area catalyst change speed increase # of particles, expose more particles agent to lower energy & or reduce container size to each other orient particles
hot increases rate increased conc. Larger surface area speeds up or starts Cold decreases rate increases rate increases rate reaction w/o being consumed..no e- bonds
Lab: hot tablet iodine clock: B2 crushed tablet flubber: w/o borax reacted faster had larger iodine reacted faster the reaction didn’t conc. so it reacted occur faster
When you finish “Sugar Water”
• Re-read your responses. Make sure they are correct and complete
• Check the vocabulary you used in your responses…is it correct (no “it, things, stuff”)\