Science 5B

Unit 2 Changes in Matter
Lesson 8 Mixing Substances Portfolio: Conclude

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   Substances                      Reaction with Baking Soda             Type of Control
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1. Water *control*              No fizzing or bubbling                     Could be Negative
Transparent                        reaction.                                            but the water
                                            After stirring, baking                        tastes salty now.
                                            soda got dissolved in                       So, if the mixture
                                            the water making it                           creates a new
                                            less transparent and salty.               substance, it is
                                                                                                        some kind of a
                                                                                                        Positive control(?)
                                         
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2. Vinegar                            Lots of fizzing and                              Positive
*control*                             bubbling with hissing 
Transparent                        sounds. 
                                             During the fizzing, 
                                             the baking soda 
                                             dissolved in the 
                                             vinegar without 
                                             stirring it.The liquid
                                             was still transparent.
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3. Olive Oil                            No fizzing                                             Negative
Semitransparente                No dissolving 
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4. Vegetable Oil                    No fizzing                                             Negative
Semitransparente                No dissolving 
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                                                                                                             Negative and/or
5. Milk                                     No fizzing                                            Positive
Opaque                                  Dissolving. Salty 
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6. Orange Juice                      Some fizzing                                      Negative and/or
Opaque                                   Dissolving. Salty                                Positive
                                                 Like EmergencyC
                                                 Vitamine powder taste
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7. Pure Beet Juice                  No fizzing                                           Negative and/or
From Concentrate                 Dissolving. Salty                                 Positive
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8. Pickled Cornichons            Lots of fizzing,                                   Positive
Juice                                        bubbling with hissing
Transparent                             sounds. 
                                                  Dissolving. The liquid
                                                  was still transparent
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9.Laundry Detergent               Some fizzing                                       Positive
Liquid
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Conclusion Statement:

Describing findings and comparing my results with Mark’s.

For my experiment, I used 9 substances when Mark used only 8. Instead of Lemonade & Apple juice, I used Pure Beet Juice and Pickled Baby Cornichons Juice.
Also we, me with my mom, went a little bit further in our experimental test and carefully tried tasting some of the substances that were safe to be tasted. So, we realized that when the baking soda dissolves in the liquids like milk, juice or water it makes the substance salty. More over, water lost its clear transparency and became blurry. We wonder now, if the new taste of the substance makes it a new substance does it mean that the reaction has a positive control? So, we couldn’t use water as a negative control standard because it is changed into a salty and a bit whitish liquid; and it wasn’t so transparent any more. Vegetable oil and Olive oil gave us pure negative control, so used as standard.
Also, we noticed that there are some sounds when the fizzing starts.

Based on my experiment,
- What are the signs that a chemical change has occurred in the observed liquids?
The signs that a chemical change has occurred in the observed liquids are fizzing or bubbling, hissing sounds, changing of taste and color, or transparency. It happens when the liquid has an acid in it as one of ingredients.

- What is the role of a control in a science experiment?
A role of a control in a science experiment is to be a standard of reference for other experiments. A control gives an indication of the kind of response in an investigation of mixing substances. There are negative and positive controls.