1. Observations and Inferences The Acid Lab

2. What is an Observation? An Observation is the act of perceiving (seeing, hearing, tasting, touching, smelling) and/or recording something with instruments. – Qualitative – uses senses, can be supported by others – Quantitative- uses numbers

3. What is an Inference? An inference is an explanation that is based on available evidence but is NOT a direct observation. - your effort to “connect the dots”

4. What do YOU see? What Observations Can you make? What Inferences can you make?

5. Observe… The three trays in front of you contain – Baking Soda: a chemical compound composed of Sodium and Carbonate (CO 3 ) – Halite: a mineral composed of Sodium (Na) and Clorine (Cl) – Calcite: a mineral composed of Calcium (Ca) and Carbonate You also have a small dropper containing a dilute solution of hydrochloric acid(HCl). Now listen to your teacher as they explain how to safely handle HCl.

6. Step 1 Turn to the page in your ISN that your teacher directs you to. Make a copy of the data table below » Reactivity of a Mineral Sample to Acid SampleEffervesce (Yes or No) Baking Soda Halite Calcite

7. Step 2 Place 2 drops (and 2 drops only) in the center of the baking soda sample. Record your observations in your data table.

8. Step 3 Repeat step 2 by dropping 2 drops of acid onto the mineral sample of Halite and recording your observations. And then the same for Calcite. Step 4 When you are done follow your teachers instructions for clean-up.

9. What Happened? Observations we made?Inferences we made?