An iron bar has a mass of 537 g. After the bar had been standing in air for a month, exactly one-eighth of the iron turned to rust (Fe2O3). Calculate the final mass of the iron bar and the rust.

The answer to your question is the mass of Iron bar = 469.87 g

                                                    mass of rust = 67.13 g

Explanation:

Data

mass of Iron bar = 537 g

1/8 turn to rust

final mass of Iron bar = x

final mass of rust = ?

Process

1.- Divide the total mass by eight (numbers of parts)

                 537g /8 = 67.13 g

2.- The final mass of rust is 1/8 = 67.13 g

3.- Calculate the final mass of the Iron bar

                 67.13 x 7 = 469.87 g

that tool would be a compass