Count the atoms for the following compounds. BELL WORK: Count the atoms for the following compounds. CA2OH 2CaC2OH 3Ca(C2OH)3 4 10 39

Preparing for TCAP… SPI 0807.9.1 The 3 subatomic particles that make up atoms are __________, __________, and __________. protons neutrons electrons SPI 0807.9.3…TRUE or FALSE Bonds do not have to be broken to form compounds. SPI 0807.9.9 The atomic mass number tells you how many protons and __________ are in an atom. neutrons

Law of Conservation of Mass Page 62 Atoms are never lost or gained in a chemical reaction…they are just rearranged. The total mass of the reactants will be equal to the total mass of the products. The starting materials in a reaction are called reactants. The substances formed from a reaction are called products.

Law of Conservation of Mass Reactants Products 4P + 5O2 P4O10 Coefficient Yield Sign Subscript If you have 14 atoms on the left side, you have to have 14 atoms on the right side!

Today’s lab…you will work as a group. Step 1: Place a baggie on the triple-beam balance. Step 2: Add baking soda to the baggie until you get a measurement of 7 grams. Step 3: Using the funnel (or dropper) and graduated cylinder, measure out 7 mL of vinegar. Step 4: Place the 7 mL of vinegar into the canister. Step 5: Put the lid on the canister. Step 6: Carefully place the canister into the baggie. Be sure to squeeze the air out of the baggie. Seal the bag…make sure it is sealed. Step 7: Measure the mass of the baggie and its contents all together. Record your measurements. Step 8: Send one member of your group to the front to record your measurements.

Today’s lab…you will work as a group. Step 9: Keeping the bag closed at all times, open the canister in the bag. Mix the vinegar with the baking soda. Record your observations. Step 10: When the reaction has stopped, measure the mass of the baggie and its contents. Record your measurement. Step 11: Send one member of your group to the front to record your measurements. Step 12: Compare the mass of the materials before the reaction and the mass of the materials after the reaction. Clean Up… Set the triple-beam balance to zero. Rinse out the canister. Throw away your baggie. Clean up your area. Push in your stool and return to your seat.

Notice: No new elements were introduced. Our experiment… NaHCO3 + CH3COOH NaOOCCH3 + H2O + CO2 Baking Soda Vinegar Sodium Acetate Water Carbon dioxide Reactants Products Notice: No new elements were introduced. On the left…Na, H, C, O On the right…Na, H, C, O