Chemical Reaction

Step 1: Understand the decomposition of ferrous sulfate (FeSO ).
Ferrous sulfate (FeSO ) is a green crystalline solid that decomposes upon strong heating. This is a common thermal decomposition reaction in chemistry. Step 2: Write the balanced chemical equation for the decomposition.
When ferrous sulfate heptahydrate (FeSO ) is heated, it first loses its water of crystallization to form anhydrous ferrous sulfate. Upon further strong heating, anhydrous ferrous sulfate decomposes into ferric oxide, sulfur dioxide, and sulfur trioxide. The balanced chemical equation for the thermal decomposition of anhydrous ferrous sulfate is: Step 3: Identify the products of the decomposition.
From the balanced equation, the products are ferric oxide (Fe O ), sulfur dioxide (SO ), and sulfur trioxide (SO ). Step 4: Compare the products with the given options.
(1) 'Fe O ': This is only one of the products.
(2) 'Fe O ' \& 'SO ': This is missing SO .
(3) 'Fe O ' \& 'SO ': This is missing SO .
(4) 'Fe O ', 'SO ' and 'SO ': This option correctly lists all the products.
(4) 'Fe O ', 'SO ' and 'SO '

Step 1: Understand the Law of Conservation of Mass.
The Law of Conservation of Mass is a fundamental principle in chemistry. It states that mass in an isolated system is neither created nor destroyed by chemical reactions or physical transformations. Step 2: Apply the law to a chemical reaction.
In the context of a chemical reaction, this law means that the total mass of the reactants before the reaction must be equal to the total mass of the products after the reaction. Atoms are rearranged, but their total quantity and mass remain constant. Step 3: Evaluate the given options based on the law.

(1) the sum of the masses of all reactants is not equal to sum of masses of all products: This statement contradicts the Law of Conservation of Mass.
(2) the sum of masses of all reactants is equal to the sum of masses of all products: This statement accurately reflects the Law of Conservation of Mass.
(3) the sum of the masses of all reactants is equal to half of sum of masses of all products: This statement contradicts the Law of Conservation of Mass.
(4) the sum of masses of all reactants is equal to double of sum of masses of all products: This statement contradicts the Law of Conservation of Mass. Step 4: Conclude the correct statement.
The Law of Conservation of Mass states that during a chemical reaction, the sum of the masses of all reactants is equal to the sum of the masses of all products. (2) the sum of masses of all reactants is equal to the sum of masses of all products.