Background

Question

Antoine Lavoisier, a prominent French chemist, conducted most of his significant work between 1772 and 1786. He established an impressive laboratory in Paris, where he welcomed scientists from around the world to collaborate and observe his experiments. Lavoisier carried out numerous controlled experiments and authored two textbooks that helped to systematize chemistry into an organized science. Due to his substantial contributions, he is often referred to as the Father of Modern Chemistry.

Lavoisier's most notable experiments involved the combustion of substances like phosphorus, sulfur, and mercury. He proposed that air consists of two parts, one of which combines with metals to create new compounds. This reactive part was later identified as oxygen. Lavoisier hypothesized that during combustion, oxygen from the air combines with a substance to form a new product. His experiments demonstrated that the mass of the new product was greater than that of the original substance by an amount equal to the oxygen that had reacted.

These experiments led to the formulation of the Law of Conservation of Mass, which states that mass cannot be created or destroyed, only converted from one form to another. Although initially met with skepticism, Lavoisier's conclusions eventually sparked a revolution in chemical thought. His work laid the foundation for Dalton’s Atomic Theory.

Directions

Examine the data for each of the following combustion experiments and answer the questions based on the analysis of the data.

Question 1
Experiment #1:



(4 points)
1. What is the mass of each reactant?

Magnesium:
Oxygen
2. The total mass of all the reactants is:

3. The total mass of the products is

Question 2
4. Does this experimental data support the Law of Conservation of Mass? Explain in full sentences.(2 points)
0 / 10000 Word Limit
Question 3
Experiment 2:

(1 point)
5. Based on the Law of Conservation of Mass, calculate the amount of magnesium that will react with all 15.0 grams of oxygen to produce 39.5 grams of magnesium oxide.

Amount of Magnesium:

Question 4
Experiment 3:

(1 point)
6. Assuming the magnesium and oxygen will react completely with one another, predict the mass of magnesium oxide that will be produced.

Magnesium Oxide:

Question 5
Experiment 4:

(1 point)
7. Predict the mass of oxygen that will be left over after the reaction of 45.7 g of magnesium and 55.2 g of oxygen.

Mass of left over oxygen in the products:

Question 6
Experiment 5:

8. Explain why the measured masses above violate the Law of Conservation of Mass. Use specific language and evidence from the reaction to support your answer. (Write in complete sentences using good grammar and spelling.)

(3 points)

Answer 1

Question 1

1. What is the mass of each reactant?

• Magnesium: (Please provide specific values if available, otherwise we can explore a hypothetical value)
• Oxygen: (Please provide specific values if available, otherwise we can explore a hypothetical value)

2. The total mass of all the reactants is:

• Total mass of reactants = Mass of Magnesium + Mass of Oxygen

3. The total mass of the products is:

• Total mass of products = Mass of Magnesium Oxide produced (please provide this value if available)

Question 2

4. Does this experimental data support the Law of Conservation of Mass? Explain in full sentences.

Yes, the experimental data supports the Law of Conservation of Mass, which states that mass cannot be created or destroyed in a chemical reaction. In the experiments, if the total mass of the reactants equals the total mass of the products, it confirms that the mass is conserved. For example, if we add the mass of magnesium and oxygen before the reaction and find that it is equal to the mass of magnesium oxide after the reaction, this agreement indicates that no mass has been lost or gained in the process.

Question 3

5. Based on the Law of Conservation of Mass, calculate the amount of magnesium that will react with all 15.0 grams of oxygen to produce 39.5 grams of magnesium oxide.

• To find the amount of magnesium that reacts, use the equation: \[ \text{mass of magnesium} + \text{mass of oxygen} = \text{mass of magnesium oxide} \] Rearranging gives: \[ \text{mass of magnesium} = \text{mass of magnesium oxide} - \text{mass of oxygen} \] \[ \text{mass of magnesium} = 39.5 , \text{grams} - 15.0 , \text{grams} = 24.5 , \text{grams} \]

Question 4

6. Assuming the magnesium and oxygen will react completely with one another, predict the mass of magnesium oxide that will be produced.

If all of the magnesium and oxygen react completely, the total mass of magnesium oxide produced can be calculated as follows: \[ \text{mass of magnesium oxide} = \text{mass of magnesium} + \text{mass of oxygen} \] (Please provide the actual mass values for magnesium and oxygen to compute this prediction.)

Question 5

7. Predict the mass of oxygen that will be left over after the reaction of 45.7 g of magnesium and 55.2 g of oxygen.

To predict the mass of leftover oxygen, follow these steps:

1. Calculate the total mass of the reactants (45.7 g Mg + 55.2 g O).
2. Determine the mass of magnesium oxide produced using the stoichiometry of the balanced chemical equation.
3. The mass of leftover oxygen would be the initial mass of oxygen minus the mass that reacted.

Let’s say the reaction produces 100 grams of magnesium oxide: \[ \text{mass of leftover oxygen} = \text{initial oxygen} - \text{mass of reacted oxygen} \] (Hypothetical calculations would need the actual amount of oxygen that reacted.)

Question 6

8. Explain why the measured masses above violate the Law of Conservation of Mass. Use specific language and evidence from the reaction to support your answer.

If the measured masses of the reactants and products do not conform to the Law of Conservation of Mass, it suggests an error in the experiment. For instance, if the total mass of the products is less than the mass of the reactants, this could mean that some of the product escaped as gas, or that the reaction was not contained properly, leading to mass loss. Alternatively, if the products weigh more than the reactants, this would suggest the addition of mass from an external source which contradicts the law. Such an occurrence would indicate a need to reassess the experimental setup and ensure that all materials are accounted for. The evidence lies within the precise measurements of reactants and products, which should equivalently demonstrate that the two sides of the reaction equation are balanced.