2.03 Conservation of Mass Activity Worksheet

In the table below, record your observations of the interactions and note if the mass was conserved. Describe the changes in properties that prove a chemical or a physical change took place.

\begin{tabular}{|c|c|c|c|c|}
\hline
& \begin{tabular}{l}
Reactants Observations \\
Before Interaction
\end{tabular}
& \begin{tabular}{l}
Products \\
Observations \\
After Interaction
\end{tabular}
& \begin{tabular}{l}
How was Mass \\
Conserved? Use \\
numbers to \\
explain your \\
answers.
\end{tabular}
& \begin{tabular}{l}
Proof of a Chemical \\
Reaction or Physical \\
Change
\end{tabular} \\
\hline
\begin{tabular}{l}
Example: \\
Steel Wool \\
+ Oxygen \\
(Fire)
\end{tabular}
& \begin{tabular}{l}
There are 6 grams of steel \\
wool. It is grey and has a \\
stringy texture. There is 1 \\
gram of oxygen in the \\
tank.
\end{tabular}
& \begin{tabular}{l}
The iron oxide is 7 \\
grams.
\end{tabular}
& \begin{tabular}{l}
Both 6 grams of \\
steel wool and 1 \\
gram of oxygen \\
were added.
\end{tabular}
& \begin{tabular}{l}
This was a chemical \\
change.
\end{tabular} \\
\hline
Egg + Heat
& \begin{tabular}{l}
There is 1 egg and 45 \\
grams of heat.
\end{tabular}
& \begin{tabular}{l}
There is one \\
cooked egg (41 \\
grams) and some \\
cracked eggshells \\
(4 grams).
\end{tabular}
& \begin{tabular}{l}
The mass is \\
conserved by the \\
heat for the egg.
\end{tabular}
& \begin{tabular}{l}
This was a physical \\
change.
\end{tabular} \\
\hline
\end{tabular}



Answer :

Sure, let's complete the table step-by-step using the given answer.

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| | Reactants Observations Before Interaction | Products Observations After Interaction | How was Mass Conserved? Use numbers to explain your answers. | Proof of a Chemical Reaction or Physical Change |
|----------------------------------------|---------------------------------------------------|----------------------------------------------------------|------------------------------------------------------------------|----------------------------------------------------------------------|
| Example: Steel Wool + Oxygen (Fire) | There are 6 grams of steel wool. It is grey with a stringy texture. There is 1 gram of oxygen in the tank. | There are 7 grams of iron oxide. | The total mass before interaction (6g steel wool + 1g oxygen) is 7 grams, which is equal to the mass after interaction (7g iron oxide). | This was a chemical reaction, as new substances (iron oxide) formed from the reactants. |
| Egg + Heat | There is 1 egg (41 grams) and 4 grams of thermal energy (heat). | There is one cooked egg (41 grams) and some broken pieces of eggshells (4 grams). | The total mass before interaction (41g egg + 4g heat) is 45 grams, which is equal to the mass after interaction (41g cooked egg + 4g eggshells). | This is a physical change, as the egg was cooked but no new substances were formed. |

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In this table, we have:

1. Reactants Observations Before Interaction: This column lists a detailed description and masses of the reactants.
- Steel Wool + Oxygen: 6 grams of steel wool and 1 gram of oxygen.
- Egg + Heat: 41 grams of egg and 4 grams of thermal energy (heat).

2. Products Observations After Interaction: This column lists a detailed description and masses of the products.
- Steel Wool + Oxygen: 7 grams of iron oxide.
- Egg + Heat: 41 grams of cooked egg and 4 grams of broken eggshells.

3. How was Mass Conserved? Use numbers to explain your answers: This column explains how the mass was conserved.
- Steel Wool + Oxygen: The sum of the masses of steel wool and oxygen (6g + 1g = 7g) equals the mass of iron oxide formed (7g).
- Egg + Heat: The sum of the masses of the egg and heat (41g + 4g = 45g) equals the mass of the cooked egg and eggshells (41g + 4g = 45g).

4. Proof of a Chemical Reaction or Physical Change: This column describes whether a chemical reaction or physical change occurred with justifications.
- Steel Wool + Oxygen: This is a chemical reaction because a new substance (iron oxide) is formed.
- Egg + Heat: This is a physical change because even though the egg changes state (cooks), no new substances are formed.