Chapter 2: Antacids

Introductory Activity – Part 1 Fill a film canister about half-full with room temperature water. Place about a quarter of a tablet of Alka-Seltzer ® in the canister and quickly push the top on. Stand back and observe. This is called an “Alka-Seltzer ® cannon.” In your lab group, brainstorm all of the chemistry involved in this process. What chemistry would you need to learn about to understand what’s happening? Share your brainstorming with the class.

Introductory Activity – Part 2 List everything you know about acids and bases. Where have you used them or come in contact with them in your life? Explain what you understand about antacids. Share your ideas with the class.

Section 2.1—Types of Matter

Matter can be classified Matter Pure Substances ElementCompound Mixtures Homogeneous (Solutions) Heterogeneous

Matter Anything that has mass and takes up space Anything made from atoms Examples:  Molecules  Cells  People  Air  Water

Pure Substances versus Mixtures MixturesPure Substances Every piece of matter is the same More than one type of matter mixed together Matter is classified as either a pure substance or a mixture

Elements versus Compounds CompoundElements Every atom is the same type of atom More than one type of atom chemically bonded together. Every molecule is the same. Pure substances are either elements or compounds

Elements Pure substance Every atom is the same Elements can be found on the periodic table! Element Single Atom Cannot be separated by chemical or physical processes

Compounds Pure substance Every molecule is the same Compound Single Molecule Made of more than one type of atom bonded together Can be separated by chemical reactions only

Mixtures Heterogeneous Homogeneous (aka “solution”) It looks the same throughout Different matter can be seen (chunks, bubbles, floaties, layers, etc.) Mixtures can be classified as homogeneous or heterogeneous

Mixtures Not a pure substance Physical combination of more than 1 type of pure substance Mixture >1 different type of matter Can be separated chemically or physically

Mixture possibilities Mixtures can be any combination of solids, liquids and gases:  Solid-solid: Medicine tablet  Solid-gas: Pop Rocks candy  Solid-liquid: Ice water  Liquid-liquid: Lemon water  Gas-Liquid: Carbonated water  Gas-Gas: Air

True solutions, Colloids & Suspensions ColloidTrue Solution Particles don’t settle out and are too small to scatter light Particles don’t settle out but are large enough to scatter light Suspension Particles will settle out over time Dissolved Particle Size Increases

Particles Scattering Light If the dissolved particles are large enough to scatter light, we say it exhibits the “Tyndall Effect” Solution Light passes through unchanged Colloids exhibit the Tyndall Effect Light is scattered by larger solute particles

Connect these concepts with Antacids What type of matter do you think antacids are?  Pure substance (Element or compound)  Mixture (homogeneous or heterogeneous)

Connect these concepts with Antacids Antacids are mixtures. They contain active & inactive ingredients What purposes could the inactive ingredients serve?

Connect these concepts with Antacids Inactive ingredients might  Add enough volume to make the pill able to be handeled  Add color  Add flavor  Allow the tablet to be compressed and formed

Let’s Practice Tin foil Example: Determine if each is element, compound, homogeneous or heterogeneous mixtures Copper pipe Concrete Carbon tetrachloride Sports drink

Let’s Practice ElementTin foil Example: Determine if each is element, compound, homogeneous or heterogeneous mixtures Element Copper pipe Heterogeneous mix Concrete Compound Carbon tetrachloride Homogenous mix Sports drink