The Fabulous Cabbage Lab Curricular Expectations: Matter as Solution, Acids and Base Knowledge Outcomes ● ● ● Identify acids, bases and neutral substances, based on measures of their pH Investigate, safely, and describe the effects of acids and bases on each other and on other substances describe and illustrate the use of biological monitoring as one method for determining environmental quality Skills - Investigate and describe the properties of materials Describe and interpret patterns in chemical reactions. Formulate operational definitions of major variables Use instruments and materials effectively and accurately for collecting data use tools and apparatus safely Materials ● 6 x 50mL beakers ● White vinegar ● Lemon juice ● Sodium Hydroxide (powder) ● Dish soap ● Cabbage solution Safety ● Personal Protective Equipment: ○ Lab coat ○ Gloves ○ Glasses ○ Closed-toed shoes ○ Hair must be up Prior to Entering: ● Do not smell solutions directly ● The cabbage smell is extremely strong- be prepared ● Wash hands immediately when skin is touched by solutions Pre-Lab Question: What is anthocyanin?(A type of pigment common in red and purple fruit and veg, acts as a pH indicator) Instructions: -Boil 300ml of distilled water and add premeasured, coarsely chopped cabbage. -Allow mixture to simmer for 10 min (research time). Drain juice into 750ml Erlenmeyer flask. Add another 300ml of distilled water to cool and dilute the solution, each lab bench can share a flask. *start here if cabbage extract is pre made* -Research how pH values are indicated specifically by anthocyanin. -Obtain one of each mystery solutions from your teacher. -Pour 40ml of anthocyanin solution into each beaker. -One at a time, add anthocyanin to one mystery solution beaker and order them from most acidic to most basic using your previous findings. -Research and predict what common household substances might have been in each solution. Record these predictions. -Dispose of all acidic solution down the drain followed by 15 seconds of running water. Repeat with remaining half of solutions. Evaluation & Assessment: 1. What colors indicate acidity vs. alkalinity? [red to pink to blue to purple to green to yellow] 2. What household substances might have these pH values? [vinegar, lemon juice, water, concentrated dish soap in water, dilute lye solution, drain cleaner or concentrated lye] 3. Would you describe anthocyanin as a technology? [Not only would I describe this as technology, I would go so far as to say this is the pinnacle of cabbage-based innovation] 4. Why is an understanding of acid-base and solution chemistry important in our daily lives and in the environment (relate the acids and bases found in everyday life)? [pH is an extremely important chemical characteristic, the environment- both internal and external to our bodies- needs to maintain relatively static (usually close to neutral) pH levels.] 5. What are two ‘real-world’ scenarios and jobs that would require the use of a pH indicator. [I used them frequently to asses water quality at my pool] Prior Learning: Grade 8- Mix and Flow of Matter 1. Investigate and describe fluids used in technological devices and everyday materials ● investigate and identify examples of fluids in household materials, technological devices, living things and natural environments ● explain the Workplace Hazardous Materials Information System (WHMIS) symbols for labelling substances; and describe the safety precautions to follow when handling, storing and disposing ofsubstances at home and in the laboratory Future connections Grade 10- Energy and Matter in Chemical Change 2. Explain, using the periodic table, how elements combine to form compounds, and follow IUPAC guidelines for naming ionic compounds and simple molecular compounds ● classify ionic and molecular compounds, acids and bases on the basis of their properties 3. Identify and classify chemical changes, and write word and balanced chemical equations for significant chemical reactions, as applications of Lavoisier’s law of conservation of mass ● describe the evidence for chemical changes; i.e., energy change, formation of a gas or precipitate, colour or odour change, change in temperature References Alberta Learning. (2016, Jan 22). Unit C: Matter and Solutions, Acids and Bases. In Chemistry 20-30 [Program of Studies]. Canada: Alberta Learning. Alberta Learning. (2017, Sept 8). Unit C: Matter and Solutions, Acids and Bases. In Science 7-89 [Program of Studies]. Canada: Alberta Learning.
