Question

State the mass law(s) demonstrated by the following experimental results, and explain your reasoning: Experiment 1: A student heats \(1.27 \mathrm{~g}\) of copper and \(3.50 \mathrm{~g}\) of iodine to produce \(3.81 \mathrm{~g}\) of a white compound; \(0.96 \mathrm{~g}\) of iodine remains. Experiment 2: A second student heats \(2.55 \mathrm{~g}\) of copper and \(3.50 \mathrm{~g}\) of iodine to form \(5.25 \mathrm{~g}\) of a white compound; \(0.80 \mathrm{~g}\) of copper remains.

Short answer

The Law of Conservation of Mass is demonstrated in both experiments, as the total mass of the reactants equals the total mass of the products.

Step-by-step solution

- Identify the Data from Experiment 1

In Experiment 1, the student heats 1.27 g of copper and 3.50 g of iodine. The total mass of the reactants is 1.27 g + 3.50 g = 4.77 g. After the reaction, 3.81 g of a white compound is produced, and 0.96 g of iodine remains unreacted. Therefore, the total mass of the products is 3.81 g + 0.96 g = 4.77 g.

- Identify the Data from Experiment 2

In Experiment 2, the second student heats 2.55 g of copper and 3.50 g of iodine. The total mass of the reactants is 2.55 g + 3.50 g = 6.05 g. After the reaction, 5.25 g of a white compound is produced, and 0.80 g of copper remains unreacted. Thus, the total mass of the products is 5.25 g + 0.80 g = 6.05 g.

- Apply the Law of Conservation of Mass

From the data in both experiments, it can be observed that the total mass of the reactants equals the total mass of the products. This demonstrates the Law of Conservation of Mass, which states that mass is neither created nor destroyed in a chemical reaction.

- Reflect on the Law of Constant Composition (if applicable)

Although the data confirms the Law of Conservation of Mass, it does not give direct information about the specific composition ratio of compounds that might reflect the Law of Constant Composition, which states that a given chemical compound always contains its component elements in a fixed ratio.

- Conclude the Demonstrated Law

Based on the provided experimental results, the Law of Conservation of Mass is demonstrated, as the total mass of the reactants equals the total mass of the products in both experiments.

Key concepts

chemical reaction

A chemical reaction involves the transformation of one or more substances into different substances. In the experiments provided, copper and iodine react to form a white compound. This process represents a chemical reaction where bonds between atoms in reactants break and new bonds form to create products.
During a chemical reaction, the following concepts are crucial:
- Reactants are the starting substances that undergo change. Here, copper and iodine are reactants.
- Products are the substances formed from the reactants. In the experiments, the white compound is the product.
The types of chemical reactions include combination, decomposition, single replacement, and double replacement. In the given experiments, copper and iodine likely undergo a combination reaction to form the white compound.

mass balance

Mass balance refers to ensuring that the total mass of reactants equals the total mass of products in a chemical reaction. This concept is deeply rooted in the Law of Conservation of Mass, which states that mass cannot be created or destroyed in a chemical reaction.
In the experiments:
- Experiment 1: The total mass of reactants (1.27 g copper + 3.50 g iodine = 4.77 g) equals the total mass of products (3.81 g white compound + 0.96 g iodine = 4.77 g).
- Experiment 2: The total mass of reactants (2.55 g copper + 3.50 g iodine = 6.05 g) equals the total mass of products (5.25 g white compound + 0.80 g copper = 6.05 g).
The balance shows that mass is conserved, illustrating the importance of mass balance in validating chemical equations and reactions.

experimental data analysis

Experimental data analysis involves collecting and interpreting data from experiments to draw meaningful conclusions. Here's how this can be applied to the given experiments:
- Data Collection: Quantities of reactants (copper and iodine) and products (white compound, remaining iodine/copper) are measured accurately.
- Calculation: Total mass of reactants and products is calculated to verify mass conservation. In both experiments, these totals matched, confirming the Law of Conservation of Mass.
- Interpretation: By comparing the reactants and products' masses, we see the mass is conserved, indicating effective measurement and reaction completion. This supports the hypothesis that mass remains constant in chemical reactions. Understanding experimental data analysis is critical in verifying scientific laws, such as the Law of Conservation of Mass, and ensuring the accuracy and reliability of experimental findings.