Day 2 Program Solutions

Transcription

1 Day 2 Program Solutions

2 Solution Definition: A solution is a homogeneous mixture of two or more substances. A solution may exist in any phase. Solution Examples: An example of a solid solution is brass. An example of a liquid solution is aqueous hydrochloric acid (HCl in water). An example of a gaseous solution is air. Solute is a substance dissolved in another substance The Solvent does the dissolving.

3 I can t believe I ate the whole thing Working with Solutions and why that s not always ideal Time to Go Green Ouch!!! How Do Sunscreens Work?

4 Potentiometric/Colorimetric Titrations

5 The Problem: A large drug store wants to market its own brand name antacid. Before they can sell the product, S2S scientists will check the test batches for potency. We will determine the amount of active antacid product by titration.

6 Antacid Experiment Learn How to assay a commercial Over The Counter (OTC) Antacid product containing CaCO 3 Learn the Use of: ph meter (potentiometric) ph Indicators (colorimetric) titration equipment Titration Curves & Equivalence Points

7 Water Ethanol Mixture

8 Prepare and explore various physical properties of solutions The Problems: How do cold packs and hand warmers work? Why does 1+1 not always equal 2 when mixing solvents

9 Define the terms: Solute Solvent Solution Ideal solution Non- Ideal Solution Solutions are prepared by dissolving a solute into a solvent Certain physical properties of solutions depend on the particular solute and solvent Solutions can be ideal or non-ideal Temperature is a measure of the energy present in a solution

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11 The Problem: Develop a more effective sunscreen. Hypothesis: To understand how sunscreens work, an understanding of how UV radiation interacts with molecules is necessary. Scientists have found that specific types of organic molecules can absorb UV light. We will examine UV absorption properties of the active ingredients in commercial sunscreens then develop our own product.

12 Determine if sunscreen molecules are UVA or UVB absorbers, or both by using UV Spectrometer UV absorbing beads Based upon your data, you will select two sunscreen molecules to prepare your own sunscreen and test it against other commercial sunscreens with SPFs of 15, 30, and 50.

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14 The Problem: More than 670 billion CD s have been sold worldwide. In an effort to cut down on environmental impact, Time Warner and Sony have commitments to reduce energy consumption and utilize recycled materials in their manufacturing operations. Hypothesis: We can determine which products are made from polystyrene and are possible resources for our recycled CDs. We can look at physical properties like solubility and density and then determine its molecular weight

15 Explain and describe polymers and plastics Explain the recycling process Identify polystyrene materials from unknowns using density and solubility Determine suitability as raw materials for the manufacturing of CD covers by determining the relative viscosity and molecular mass

16 I can t believe I ate the whole thing: acids and bases Working with Solutions and why that s not always ideal: Ideal Solutions Time to Go Green: recycle/ viscosity Ouch!!! How Do Sunscreens Work? sunscreens

17 General information General middle school: general Science buddies: projects Ideal Solutions Hot ice: exothermic Cold pack from hot ice: endothermic Citric acid cold pack: endothermic 2

18 Time to Go Green/ Polymers Slime: slime Polymer experiments: cornell Density rainbow: demo ; hands on Bouncing ball: polymer ball I can t believe I ate the whole thing/ Acids and bases Disappearing ink: acid base 2 Cabbage juice indicator: acid base 1 Sunscreen Sunscreen experiments: sunscreen; sunscreen2