Nelson Lab 4.1: Evidence of Chemical Reactions
INFORMAL​ - ​Write directly on this pdf in Notability. No need to create a separate document. You will *not* be turning this
in, but make sure you answer all questions and understand all concepts.
The purpose of this investigation is to observe reactions that provide evidence of chemical changes. For each combination of
substances given, assume that if any chemical change occurs, it happens rapidly at room temperature. TWO of the steps in the
procedure will give you NO Reaction.​ Problem​: What evidence, if any, shows that a chemical change has occurred when the
following substances are mixed?
Pre-Lab Questions:
***​WATCH​ this video ​FIRST​: ​ ​https://www.flinnsci.com/how-to-use-a-bunsen-burner-safely/vht0324/
1. Label the following as Physical Properties (PP) or Chemical Properties (CP):
Color:_____
Density:_____
Flammability: _____
Solubility: _____
Melting Pt: _____
New Odor: _____ Malleability: _____ Gas Produced: _____ Reacts with Acid: _____
2. What are some examples of evidence of a chemical reaction?
3. ​Write out the formulas of each of the REACTANTS for each labeled station in the spaces provided in the Procedure.
**​FYI​ - anything that ​appears​ as a liquid in this lab, is aqueous (AQ) unless it’s water!
Procedure
1. Combine the substances according to the instructions provided for each station, and record all observations
before, during, and after the mixing in the space provided. Then label the type of change (Physical Change {∆} or
Chemical Change {∆})​ and list the Evidence of a reaction taking place, ​if​ there was a chemical change.
2. Clean the lab station thoroughly before proceeding to the next station.
Stations:
1. A zinc strip is placed into a hydrochloric acid solution for 2 minutes.
REACTANTS​:
Zn(s) + HCl(aq) ⇒
PRODUCTS (later)​:
Observations:
Type of Change: ​Phys ∆/Chemical ∆ (​circle one)
Evidence of a Reaction:
2. A couple of drops of bromothymol blue solution are added to a squirt of hydrochloric acid.
Observations:
Type of Change: ​Phys ∆/Chemical ∆ (​circle one)
Evidence of a Reaction:
3. А few drops of silver (I) nitrate solution are added to a squirt of hydrochloric acid.
REACTANTS​: __________________________________________________
PRODUCTS (later)​:
Observations:
Type of Change: ​Phys ∆/Chemical ∆ (​circle one)
Evidence of a Reaction:
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4. A squirt of Hydrochloric acid is added to a squirt of sodium acetate solution.
REACTANTS​: __________________________________________________
PRODUCTS (later)​:
Observations:
Type of Change: ​Phys ∆/Chemical ∆ (​circle one)
Evidence of a Reaction:
5. Ammonium nitrate crystals are stirred into some water.
REACTANTS​: __________________________________________________
PRODUCTS (later)​:
Observations:
Type of Change: ​Phys ∆/Chemical ∆ (​circle one)
Evidence of a Reaction:
6. A squirt of Hydrochloric acid is added to a squirt of sodium bicarbonate solution.
REACTANTS​: __________________________________________________
PRODUCTS (later)​:
Observations:
Type of Change: ​Phys ∆/Chemical ∆ (​circle one)
Evidence of a Reaction:
7. A couple of drops of phenolphthalein solution are added to a squirt of ammonia ​(NH​3​- aka Nitrogen Trihydride) ​solution.
Observations:
Type of Change: ​Phys ∆/Chemical ∆ (​circle one)
Evidence of a Reaction:
8. A squirt of Sodium hydroxide solution is added to a squirt of cobalt(II) chloride solution.
REACTANTS​: __________________________________________________
PRODUCTS (later)​:
Observations:
Type of Change: ​Phys ∆/Chemical ∆ (​circle one)
Evidence of a Reaction:
9. A squirt of Sodium nitrate solution is added to a squirt of potassium chloride solution.
REACTANTS​: __________________________________________________
PRODUCTS (later)​:
Observations:
Type of Change: ​Phys ∆/Chemical ∆ (​circle one)
Evidence of a Reaction:
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10. A piece of copper wire is placed into a squirt of silver (I) nitrate solution.
REACTANTS​: __________________________________________________
PRODUCTS (later)​:
Observations:
Type of Change: ​Phys ∆/Chemical ∆ (​circle one)
Evidence of a Reaction:
Write out the full equation for each reaction below. Be sure to include ​states​. We ​will​ BALANCE the reactions ​later.​
Write N/A if there wasn’t a spot for reactants. Write “NO RXN” if there was no chemical reaction.
1) ​Zn(s) + HCl(aq) ⇒
2) N/A
3)
4)
5)
6)
7) N/A
8)
9)
10)
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