Rust is formed by the interaction of iron and oxygen. When rust formed on an iron nail with a mass of 100 g, the mass of the rusted nail was 143 g. What mass of oxygen gas most likely reacted with the iron nail?

Group of answer choices

243 g

100 g

50 g

43 g

1 answer

To find the mass of oxygen gas that reacted with the iron nail, we can use the information about the mass of the iron nail and the mass of the rusted nail.

  1. The initial mass of the iron nail before rusting is 100 g.
  2. The mass of the rusted nail after rusting is 143 g.

The increase in mass due to the formation of rust is calculated as follows:

\[ \text{Mass of rust} = \text{mass of rusted nail} - \text{mass of iron nail} \]

\[ \text{Mass of rust} = 143 , \text{g} - 100 , \text{g} = 43 , \text{g} \]

This increase in mass (43 g) comes from the oxygen gas that reacted with the iron to form rust (iron oxide).

Therefore, the mass of oxygen gas that reacted with the iron nail is:

\[ \boxed{43 , \text{g}} \]