Summer SAVY Session 2, Day 2 – Common and Practical Chemistry (Pao)
Day 2: We had fun learning about acids and bases and reviewing polarity today, and all students worked hard to understand the material. First, we made butter by shaking heavy cream. Students collectively generated an explanation that when we shake the cream, the nonpolar fat molecules clump together while the polar water molecules stick together. Then, students watched a demonstration in which a flame was extinguished using carbon dioxide, produced by an acid-base reaction between baking soda and vinegar. We discussed what acids and bases are and worked through practice problems in order to identify substances as acidic or basic by looking at a chemical equation. We also did an online simulation to understand the relationship between pH and hydronium in everyday substances, and then we investigated different types of water and beverages to determine the pH using pH paper. Because some brands advertise their water as alkaline (basic) and mark up the price, we wanted to see if they actually were! We found that alkaline waters did have a higher pH (basic) than substances like lemon juice, water from the water fountain, and Sprite. We also investigated the relationship between pH and gas production in pop rocks.
Some key takeaways from today include:
- The components of chemical equations, including reactants, products, subscripts, superscripts, and the reaction arrow, allow us to understand how a chemical reaction proceeds.
- Acids donate H+, and bases accept H+. Acids and bases can be identified in an equation by examining which compounds add or subtract an H+.
- Acids and bases also have different characteristics. For example, acids are often sour, whereas bases are often bitter.
- Indicators can test if a substance is acidic or basic based on the pH scale. Acids have a low pH, which correlates to a high concentration of H+, whereas bases have a high pH and a low concentration of H+.
If you would like to ask your child some dinner table questions, you could ask:
- What are some examples of acids and bases in our home?
- What are some characteristics of acids and bases? Why might it be important to know the difference between them?
- How can you tell if a substance is an acid or base by looking at the chemical equation?
I am looking forward to day 3 of SAVY, where students will learn about ionic and covalent bonding.
Have a great evening,
Ms. Pao