1. Identify a few household substances (i.e., soap, water, salt, milk, etc.) that produce a chemical reaction when combined. Create a model of the reaction
2. Describe an experiment with these substances. Include how to record data that provides evidence of a chemical reaction.
3. Use the models to describe the new substances formed. Show that mass was conserved.
1. One example of household substances that produce a chemical reaction when combined is the reaction between vinegar (acetic acid) and baking soda (sodium bicarbonate). The reaction can be represented by the following equation:
CH3COOH (acetic acid) + NaHCO3 (sodium bicarbonate) → CH3COONa (sodium acetate) + H2O (water) + CO2 (carbon dioxide gas)
2. Experiment:
a) Gather the following materials: vinegar, baking soda, a clear plastic cup or container, a tablespoon, a balloon, and a scale.
b) Start by measuring 1 tablespoon of baking soda using the scale and place it into the plastic cup.
c) Pour enough vinegar into the cup to cover the baking soda.
d) Quickly place the balloon over the opening of the cup without letting the vinegar and baking soda mixture spill out.
e) Observe the reaction and record your observations.
f) After the reaction has finished (the balloon has inflated or until no more gas is produced), carefully remove the balloon from the cup.
g) Measure the mass of the inflated balloon using the scale.
h) Empty the contents of the cup and rinse it thoroughly.
3. New substances formed:
When vinegar (acetic acid) reacts with baking soda (sodium bicarbonate), several new substances are formed: sodium acetate (CH3COONa), water (H2O), and carbon dioxide gas (CO2).
To show that mass was conserved in this reaction, the mass of the reactants (vinegar and baking soda) should be equal to the mass of the products (sodium acetate, water, and carbon dioxide). By measuring the mass of the inflated balloon after the reaction, you can compare it to the initial mass of the vinegar and baking soda mixture.
If the mass of the inflated balloon is equal to or very close to the initial mass of the vinegar and baking soda, it demonstrates that mass was conserved during the reaction.
1. Here are a few household substances that can produce a chemical reaction when combined:
- Vinegar (acetic acid) and baking soda (sodium bicarbonate)
- Hydrogen peroxide and yeast
- Iron (nail) and vinegar
- Bleach (sodium hypochlorite) and ammonia
Now, let's create a model for one of these reactions:
Model: Vinegar and Baking Soda Reaction
CH3COOH (acetic acid) + NaHCO3 (sodium bicarbonate) → CO2 (carbon dioxide) + H2O (water) + NaC2H3O2 (sodium acetate)
2. Experiment: Vinegar and Baking Soda Reaction
Materials:
- Vinegar (acetic acid)
- Baking soda (sodium bicarbonate)
- Measuring spoon
- Glass or beaker
- Balloon
- Stopwatch or timer
Procedure:
1. Measure one tablespoon of baking soda and place it in the glass or beaker.
2. Measure one tablespoon of vinegar and pour it into the glass containing the baking soda.
3. As soon as the vinegar is added, quickly place the balloon over the mouth of the glass, making sure it is sealed tightly.
4. Start the stopwatch or timer and observe the reaction for a few minutes.
5. Record any observations, such as changes in color, temperature, or the inflation of the balloon.
Data recording:
- Record the initial measurements of vinegar and baking soda used.
- Note the start time of the reaction.
- Record any noticeable changes in the appearance or behavior of the substances, such as effervescence (bubbling), gas production, or changes in color.
- Measure the final mass of the products (the sodium acetate and any remaining baking soda) after allowing the reaction to complete and all gas to escape.
3. Using the models to describe the new substances formed and show that mass was conserved:
In the vinegar and baking soda reaction, acetic acid (CH3COOH) and sodium bicarbonate (NaHCO3) react to form carbon dioxide gas (CO2), water (H2O), and sodium acetate (NaC2H3O2). These new substances have different properties and composition than the reactants.
To show that mass was conserved, you can calculate the mass of the reactants (vinegar and baking soda) and the mass of the products (sodium acetate and any remaining baking soda). The total mass of the products should be equal to the total mass of the reactants, indicating that no mass was lost or gained during the reaction.
1. Here are a few examples of household substances that can produce a chemical reaction when combined:
- Baking soda and vinegar: When mixed together, they produce carbon dioxide gas, which creates fizzing and bubbling.
- Hydrogen peroxide and yeast: When combined, a reaction occurs that releases oxygen gas, resulting in a foaming effect.
- Lemon juice and baking soda: When mixed, they create a chemical reaction that produces carbon dioxide gas and forms a bubbly mixture.
Now, let's create a model of the reaction between baking soda and vinegar:
The chemical equation is:
Baking soda (sodium bicarbonate, NaHCO3) + Vinegar (acetic acid, CH3COOH) → Sodium acetate (CH3COONa) + Water (H2O) + Carbon dioxide (CO2)
2. Here is an experiment using baking soda and vinegar to demonstrate a chemical reaction and how to record data for evidence:
- Materials needed: Baking soda, vinegar, clear glass or plastic cup, measuring spoons, measuring cup, stopwatch, and a balloon.
- Procedure:
1. Measure 1 tablespoon of baking soda and place it into the cup.
2. Measure ¼ cup of vinegar and pour it into the cup with the baking soda.
3. Quickly place the balloon over the top of the cup, ensuring a tight seal.
4. Start the stopwatch and observe the reaction.
5. Record the time it takes for the balloon to inflate fully or until no more gas is released.
The evidence of a chemical reaction would be the inflation of the balloon due to the release of carbon dioxide gas. By measuring the time it takes for the balloon to inflate, you can collect data that provides evidence of the chemical reaction occurring. Repeat the experiment multiple times to get consistent results and take note of any variations or trends in the data.
3. In the model reaction between baking soda and vinegar, the new substances formed are sodium acetate (CH3COONa), water (H2O), and carbon dioxide (CO2). Sodium acetate is a salt, while water and carbon dioxide are compounds.
To show that mass is conserved, you can carefully measure the initial mass of the baking soda and vinegar mixture before the reaction and compare it to the final mass of the products after the reaction. If the experiment is conducted in a close system (without any gas escaping), the mass of the reactants should be equal to the mass of the products, thus demonstrating the conservation of mass.