Question

fe + s → fes
reading check integrate with visuals explain how the masses on the scales in figure 4 demonstrate the law of conservation of mass.

Explanation:

Step1: Calculate the total mass of reactants

For the reaction \(Fe + S
ightarrow FeS\), the mass of \(Fe\) is \(14.0g\) and the mass of \(S\) is \(8.0g\). The total mass of reactants is \(14.0 + 8.0=22.0g\), which is equal to the mass of \(FeS\) (\(22.0g\)).

Step2: Calculate the mass change in the liquid - related part

The mass of the empty beaker is \(80.5g\). After adding some liquid (mass of beaker + liquid \(92.8g\)), the mass of the liquid is \(92.8 - 80.5 = 12.3g\). When another liquid is added (mass of beaker + two liquids \(173.3g\)), the mass of the second liquid is \(173.3-92.8 = 80.5g\). The total mass of the two - added liquids is \(12.3+80.5 = 92.8g\), which shows that mass is conserved (the sum of the masses of substances before and after a physical or chemical change is the same).

Answer:

In the chemical reaction \(Fe + S
ightarrow FeS\), the sum of the masses of \(Fe\) (\(14.0g\)) and \(S\) (\(8.0g\)) is \(14.0 + 8.0=22.0g\), which equals the mass of \(FeS\) (\(22.0g\)). For the liquid - beaker system, by calculating the mass of each liquid added (\(92.8 - 80.5 = 12.3g\) for the first liquid and \(173.3 - 92.8=80.5g\) for the second liquid), the sum of the masses of the added liquids (\(12.3 + 80.5 = 92.8g\)) shows that mass is conserved. So, these mass measurements demonstrate the law of conservation of mass (the total mass of substances before a change is equal to the total mass of substances after the change).