Question

part a the students data can be seen here. a chemical reaction clearly took place in the flask. one entry is missing: the mass of the system at the end of the experiment. what amount should be added to the data table? a 485.68g b less than 485.68g c more than 485.68g d cannot be determined part b ms. sossman, the science teacher wrote a partial equation for the reaction on the whiteboard. fe + o₂ → fe₂o₃ using the law of conservation of mass as your guide, balance this chemical equation. a 2fe + 3o₂ → fe₂o₃ b 2fe + o₂ → fe₂o₃ c 4fe + 3o₂ → 2fe₂o₃

Explanation:

Part A

Step1: Apply law of conservation of mass

In a closed - system chemical reaction, the total mass before and after the reaction remains the same. Since no information is given about mass loss (like gas escaping etc., assuming it's a closed system), the mass at the end of the experiment should be the same as the initial mass if no mass is lost to the surroundings.

Part B

Step1: Balance iron atoms

On the left - hand side, we have 1 Fe atom and on the right - hand side, we have 2 Fe atoms in \(Fe_2O_3\). To balance Fe, we put a 4 in front of Fe on the left - hand side: \(4Fe+O_2
ightarrow Fe_2O_3\).

Step2: Balance oxygen atoms

On the left - hand side, we have 2 oxygen atoms in \(O_2\) and on the right - hand side, we have 3 oxygen atoms in \(Fe_2O_3\). To balance oxygen, we put a 3 in front of \(O_2\) and a 2 in front of \(Fe_2O_3\) to get \(4Fe + 3O_2
ightarrow2Fe_2O_3\).

Answer:

Part A: A. 485.68g
Part B: C. \(4Fe + 3O_2
ightarrow2Fe_2O_3\)