Catalyst – September 2(11), 20091. Label the following as either a pure

substance (PS) mixture (M):a) Salt waterb) Hydrogenc) Salad

2. Dr. Spock performed a reaction in space. The mass of the reactants was 46.3 grams. The mass of the products was 77.5 grams. Did Dr. Spock’s reaction obey the LCM? Why or why not?

Today’s Agenda

Catalyst Quiz Mastery Tracking Finish planning LCM Lab LCM Lab and Lab Report Exit Question

Today’s Objectives

SWBAT plan and conduct an experiment to prove the Law of Conservation of Matter.

Law of Conservation of Matter (LCM)

Key Point #1: The Law of Conservation of Matter states that matter cannot be created or destroyed, only changed from one form of matter to another.

What goes in must come out!

LCM and Physical Changes

# ParticlesBeginning Stuff = # ParticlesEnding

Stuff

MassBeginning Stuff = MassEnding Stuff

Cut

LCM and Physical Change

# ParticlesBeginning Stuff = # ParticlesEnding

Stuff

MassBeginning Stuff = MassEnding Stuff

Dissolve

LCM and Chemical Change

MassReactants = MassProducts

Chemical Reaction

New Substance

LCM and Chemical Change

MassReactants = MassProducts

Chemical Reaction

Particles Rearrange

Example of a Good Conclusion

The reaction between baking soda and vinegar does obey the Law of Conservation of Matter. The LCM states that matter cannot be created or destroyed. That means that the mass of the reactants should equal the mass of the products. At the start of this reaction, there were ## grams of reactants. After the reaction, there were ## grams of products. These masses are very similar/the same; therefore the reaction obeyed the LCM. (The masses are not exactly the same because of experimental error.)

Example of a Good Conclusion

“The reaction between baking soda and vinegar

does obey the Law of Conservation of Matter.”

This is the statement of what you think!!!

Example of a Good Conclusion

The reaction between baking soda and vinegar does obey the Law of Conservation of Matter. The LCM states that matter cannot be created or destroyed. That means that the mass of the reactants should equal the mass of the products. At the start of this reaction, there were ## grams of reactants. After the reaction, there were ## grams of products. These masses are very similar/the same; therefore the reaction obeyed the LCM. (The masses are not exactly the same because of experimental error.)

Example of a Good Conclusion

“The LCM states that matter cannot be created or destroyed.

That means that the mass of the reactants should equal the

mass of the products.”

This explains background information – helps support your

conclusion.

Example of a Good Conclusion

The reaction between baking soda and vinegar does obey the Law of Conservation of Matter. The LCM states that matter cannot be created or destroyed. That means that the mass of the reactants should equal the mass of the products. At the start of this reaction, there were ## grams of reactants. After the reaction, there were ## grams of products. These masses are very similar/the same; therefore the reaction obeyed the LCM. (The masses are not exactly the same because of experimental error.)

Example of a Good Conclusion

“At the start of this reaction, there were ## grams of

reactants. After the reaction, there were ##

grams of products.”

This is what happened in the experiment.

Example of a Good Conclusion

The reaction between baking soda and vinegar does obey the Law of Conservation of Matter. The LCM states that matter cannot be created or destroyed. That means that the mass of the reactants should equal the mass of the products. At the start of this reaction, there were ## grams of reactants. After the reaction, there were ## grams of products. These masses are very similar/the same; therefore the reaction obeyed the LCM. (The masses are not exactly the same because of experimental error.)

Example of a Good Conclusion

“These masses are very similar/the same;

therefore the reaction obeyed the LCM.”

This ties back into what you think!

Example of a Good Conclusion

The reaction between baking soda and vinegar does obey the Law of Conservation of Matter. The LCM states that matter cannot be created or destroyed. That means that the mass of the reactants should equal the mass of the products. At the start of this reaction, there were ## grams of reactants. After the reaction, there were ## grams of products. These masses are very similar/the same; therefore the reaction obeyed the LCM. (The masses are not exactly the same because of experimental error.)

Can YOU prove the LCM?

In your group, you will plan a procedure for proving the Law of Conservation of Matter

You will perform the lab tomorrow You may perform ONE of the following

reactions: Baking soda + vinegar Alka Seltzer + water

You must complete an entire Lab Report for Homework (due Tuesday in class or Wednesday at the beginning of class)

Available Materials

Balance Graduated

cylinder Beaker Zip-Loc baggie Funnel Spatula Petri dish Test Tubes

Glass stirring rod 1 Alka Seltzer

tablet Up to 25 mL of

water Up to 3 grams of

baking soda Up to 25 mL of

vinegar

Exit Question

The goal of a car airbag is to slow a passenger's forwardmotion as evenly as possible in a fraction of a second. Theairbag's inflation system reacts toxic sodium azide (NaN3)with potassium nitrate (KNO3) to produce nitrogen gas

andsodium metal. Hot blasts of the nitrogen inflate the

airbag. In a Honda Civic, there are about 500 grams of sodiumazide (NaN3) in its airbag before inflation. It decomposes

to 323 grams of nitrogen gas. Question: How much sodium metal is produced?

Your Task: Answer the question and support your answer with a quality conclusion.