Question

Alice and Marge are studying the properties of matter. The girls placed some an iron nail in a beaker containing water. Iron is a solid metal at room temperature. Iron is a shiny and malleable; it can be formed into shapes like the nails the girls used. Iron will turn reddish-brown in the presence of air or water as it rusts. Iron is a good conductor of electricity and heat. After 48 hours, the girls checked the nail in the water and compared it to the nail they left on the lab bench. Based on the girls' experiment, what is a chemical property of iron?
A) Iron is malleable. B) Iron rusts in water. C) Iron is a strong metal. D) Iron is a good conductor.

Answer 1

Answer: B) Iron rusts in water.

Explanation:

Physical property is defined as the property of a substance which becomes evident during physical changes. Example: Melting point  , electrical conductivity, malleability,

Chemical property is defined as the property of a substance which becomes evident during chemical changes. Example: Reactivity with other substances

Rust is hydrated ferric oxide $(Fe_2O_3.xH_2O$.

$Fe\rightarrow Fe^{2+}+2e^-$

Corrosion of iron is called as rusting. Rust is hydrated ferric oxide $(Fe_2O_3.xH_2O$.

$Fe\righatarrow Fe^{2+}+2e^-$

$O_2+4H^++4e^-\rightarrow 2H_2O$

$4Fe^{2+}+O_2+4H_2O\rightarrow 2Fe_2O_3+8H^+$

Thus rusting of iron is a chemical property.

Answer 2

Answer: B) Iron rusts in water.