Which of the following demonstrates a chemical change? point)
vaporizing sugar and water mixing to create sugar water (Fe) reacting to water (H 2 O)) and oxygen() to form iron oxide (F*e_{2}*O_{3}) steam.condensing on a mirror
The following options demonstrate a chemical change:
1) (Fe) reacting to water (H2O) and oxygen (O2) to form iron oxide (Fe2O3). This is a chemical reaction where the iron reacts with water and oxygen to form a different compound, iron oxide.
2) Steam condensing on a mirror. This is a physical change where water vapor (steam) turns into liquid water when it comes into contact with a cooler surface (the mirror).
The chemical change among the options provided is:
Iron (Fe) reacting with water (H2O) and oxygen (O2) to form iron oxide (Fe2O3).
Among the options given, the reaction where iron (Fe) reacts with water (H2O) and oxygen (O2) to form iron oxide (Fe2O3) demonstrates a chemical change.
To understand why it is a chemical change, let's break down the process and focus on the key aspects.
1. Iron (Fe) reacts with water (H2O): When iron combines with water, a chemical reaction occurs that leads to the formation of iron oxide. This is represented by the following equation:
2 Fe + 3 H2O -> Fe2O3 + 3 H2
In this reaction, the iron atoms (Fe) interact with water molecules (H2O) to form iron oxide (Fe2O3) and hydrogen gas (H2). This is a chemical change because the original substances - iron and water - are transformed into new substances with different properties - iron oxide and hydrogen gas.
2. Formation of iron oxide (Fe2O3): In this step, the iron atoms (Fe) combine with oxygen (O2) from the air to form iron oxide (Fe2O3). This reaction can be represented as follows:
4 Fe + 3 O2 -> 2 Fe2O3
The iron atoms (Fe) and oxygen molecules (O2) rearrange their atoms to create a new compound, iron oxide (Fe2O3). This is also a chemical change because new substances with different properties are formed.
In summary, the reaction where iron reacts with water and oxygen to form iron oxide demonstrates a chemical change since it involves the rearrangement of atoms and the creation of new substances.