What choice demonstrates the Law of Conservation of Mass?
[tex]194 g HNO _3 \rightarrow 180 g NO _2+32 gO _2+36 g H _2 O[/tex]
[tex]110 g Ag _2 O \rightarrow 107 g Ag +32 g O _2[/tex]
[tex]98 g CaCO _3 \rightarrow 56 g CaO ^{+} 44 g CO _2[/tex]
[tex]30 g LiO _2+44 g CO _2 \rightarrow 74 g LiCO _3[/tex]
Answer (1)
The Law of Conservation of Mass states that the total mass of reactants equals the total mass of products.
Calculate the total mass of reactants and products for each reaction.
Compare the total masses to identify the reaction that obeys the law.
Reaction 4 ( 30 gL i O 2 + 44 g C O 2 → 74 gL i C O 3 ) demonstrates the Law of Conservation of Mass because the total mass of reactants (74 g) equals the total mass of products (74 g). 30 gL i O 2 + 44 g C O 2 → 74 gL i C O 3
Explanation
Understanding the Law of Conservation of Mass The Law of Conservation of Mass states that mass is neither created nor destroyed in a chemical reaction. This means the total mass of the reactants must equal the total mass of the products. We need to check each reaction to see which one obeys this law.
Analyzing Each Reaction Let's analyze each reaction:
Reaction 1: 194 g H N O 3 → 180 g N O 2 + 32 g O 2 + 36 g H 2 O The total mass of the reactants is 194 g. The total mass of the products is 180 + 32 + 36 = 248 g. Since 194 g = 248 g, this reaction does not demonstrate the Law of Conservation of Mass.
Reaction 2: 110 g A g 2 O → 107 g A g + 32 g O 2 The total mass of the reactants is 110 g. The total mass of the products is 107 + 32 = 139 g. Since 110 g = 139 g, this reaction does not demonstrate the Law of Conservation of Mass.
Reaction 3: 98 g C a C O 3 → 56 g C a O + 44 g C O 2 The total mass of the reactants is 98 g. The total mass of the products is 56 + 44 = 100 g. Since 98 g = 100 g, this reaction does not demonstrate the Law of Conservation of Mass.
Reaction 4: 30 gL i O 2 + 44 g C O 2 → 74 gL i C O 3 The total mass of the reactants is 30 + 44 = 74 g. The total mass of the products is 74 g. Since 74 g = 74 g, this reaction demonstrates the Law of Conservation of Mass.
Conclusion Therefore, the reaction that demonstrates the Law of Conservation of Mass is: 30 gL i O 2 + 44 g C O 2 → 74 gL i C O 3
Examples
The Law of Conservation of Mass is crucial in various real-world applications, such as in chemical industries where precise calculations are needed to ensure that the amount of reactants used equals the amount of products obtained. For example, in the production of ammonia ( N H 3 ) from nitrogen ( N 2 ) and hydrogen ( H 2 ), the mass of N 2 and H 2 used must equal the mass of N H 3 produced. This principle is also used in environmental science to track pollutants and understand chemical reactions in the atmosphere and water bodies, ensuring that mass is accounted for in every process.
