Em um frasco foram misturados 4g de reagente a com 10g de reagente b, obtendo 11,1g de produto

General
1

em um frasco foram misturados 4g de reagente a com 10g de reagente b, obtendo 11,1g de produto e um excesso de 2,9g de reagente b. em um outro frasco foram misturados 16g de reagente a com 35,5g de reagente b. determine a massa de produto e a massa do reagente em excesso. mostre que a reação química segue a lei de lavoisier e a lei de proust.

2

What is the problem described in the conversation?

Answer:
The problem described in the conversation involves mixing different amounts of reactants and observing the resulting products to determine the mass of the product and the excess reactant. Additionally, it aims to demonstrate the validity of the Law of Conservation of Mass by Antoine Lavoisier and the Law of Definite Proportions by Joseph Proust in the chemical reaction.

What are the steps to solve the given problem?

Answer:

  1. Determine the moles of each reactant in both experiments.
  2. Identify the limiting reactant based on stoichiometry calculations.
  3. Calculate the mass of the product formed using the limiting reactant.
  4. Calculate the mass of the excess reactant in each case.
  5. Verify that the reaction obeys the Law of Conservation of Mass and the Law of Definite Proportions by showing that the total mass of reactants equals the total mass of products in each case.

Solution:

  1. Determine the moles of each reactant in the first experiment:

    • The molar mass of reagent a (\text{A}) is 4 g.
    • The molar mass of reagent b (\text{B}) is 10 g.
    • The mass of the product is 11.1 g, and the excess of reagent b is 2.9 g.

    The number of moles of reagent a (n_{\text{A}}) is calculated as \frac{4 \text{ g}}{4 \text{ g/mol}} = 1 \text{ mol}.

    The number of moles of reagent b (n_{\text{B}}) is calculated as \frac{10 \text{ g}}{10 \text{ g/mol}} = 1 \text{ mol}.

  2. Identify the limiting reactant:

    Reagent a is the limiting reactant because it produces less product when considering the stoichiometry of the reaction.

  3. Calculate the mass of the product:

    The molar mass of the product is calculated as (1 \text{ mol} \times 11.1 \text{ g/mol}) = 11.1 \text{ g}.

  4. Calculate the mass of the excess reactant:

    The mass of the excess reagent b is given as 2.9 g.

  5. Verify the Laws of Conservation of Mass and Definite Proportions:

    • Law of Conservation of Mass: The total mass of reactants (14 g) is equal to the total mass of products (11.1 g) in the first experiment, supporting this law.
    • Law of Definite Proportions: The constant mass ratios of reactants and products in the reaction support this law as well.

Following these steps ensures that the reaction described adheres to the fundamental principles of chemistry laid out by Lavoisier and Proust.