Question

If a spoon of copper metal is placed in a solution of \(\mathrm{FeSO}_{4} .\) What will be the correct observation? (a) Copper is dissolved in \(\mathrm{FeSO}_{4}\) to give brown deposit. (b) No reaction takes place. (c) Iron is deposited on copper spoon. (d) Both copper and iron are precipitated.

Short answer

No reaction takes place when a copper spoon is placed in a solution of \(\mathrm{FeSO}_4\), as copper is less reactive than iron and cannot displace it.

Step-by-step solution

Understanding Reactivity

Before predicting the outcome of the reaction, understand the reactivity of metals involved. Copper (Cu) and Iron (Fe) are both metals, and their ability to displace each other depends on their position in the reactivity series. The reactivity series is a list of metals arranged in order of decreasing reactivity. In this series, iron is more reactive than copper.

Predicting the Reaction

Since iron is more reactive than copper, it will tend to remain in the solution rather than being displaced by copper. Copper cannot displace iron from its compound (iron sulfate, \(\mathrm{FeSO}_4\)) because copper is less reactive. Hence, no reaction will take place between copper metal and a solution of iron sulfate.

Observing the Outcome

Upon placing the copper spoon in the \(\mathrm{FeSO}_4\) solution, we should observe that there is no visible reaction. There will be no brown deposit (which would indicate the presence of copper) or iron deposit on the copper spoon.

Concluding the Correct Observation

Based on the reactivity series and the inability of copper to displace iron from iron sulfate, the correct observation is that no reaction will take place when a spoon of copper is placed in a solution of \(\mathrm{FeSO}_4\). Therefore, option (b) 'No reaction takes place.' is the correct answer.

Key concepts

Chemical Reactivity

When we talk about chemical reactivity, we're exploring the tendency of a substance to engage in chemical reactions. Reactivity is an essential concept that determines how a substance will behave when it encounters another substance. For metals, this is often measured by their ability to undergo certain types of reactions, such as oxidation or displacement reactions. In the classroom, students often learn about the reactivity series, a helpful tool that organizes common metals by their reactivity.

The reactivity series lists metals from most reactive to least reactive. Highly reactive metals, like alkali metals, are quick to participate in reactions, whereas noble metals like gold are much more resistant to reacting. The position of a metal in this series can predict its behavior in displacement reactions. Understanding this hierarchy helps in predicting the outcomes of reactions in exercises.To solidify your knowledge, try to remember or visualize the reactivity series, and when faced with an exercise, determine where the involved metals stand in the series. This step is pivotal as it lays the foundation for predicting the chemical behavior of metals.

Metal Displacement Reaction

A metal displacement reaction is a type of redox reaction where a more reactive metal displaces a less reactive metal from its compound. The fundamental principle behind this is the comparative reactivity of the involved metals. In these reactions, metals can swap places, with the more assertive metal taking the seat of the less reactive one in a compound.

For example, if you place a metal in the solution of another metal's salt, there's potential for a displacement reaction. If the metal is more reactive than the one in the compound, it will displace it, forming a new compound and freeing the less reactive metal. Teachers often demonstrate this with the classic copper and silver nitrate reaction, where copper displaces silver due to its higher reactivity.Educationally, visualize a simple scenario akin to a competition where the 'stronger' metal wins and replaces the 'weaker' one. Students should look at the metals in the scenario and judge who will 'stay' and who will 'go' based on the reactivity series.

Copper and Iron Reactivity

With copper and iron reactivity, we encounter two well-known metals in the reactivity series. Copper is a less reactive metal, often found later in the series, while iron is more reactive and placed earlier on the list. This knowledge is crucial when predicting reactions between iron and copper compounds. In our exercise scenario, the copper cannot react with the iron sulfate solution to cause a displacement.

Understanding why copper cannot replace iron involves grasping that copper atoms do not have enough reactivity to force iron atoms out of their compound. This contrasts with more reactive metals like zinc or magnesium, which could displace iron from iron sulfate. Educators may illustrate this concept by contrasting copper with these more reactive metals. Here, it's helpful to think of copper as being 'content' where it is, and not 'ambitious' enough to replace iron from its compound.When tackling textbook exercises involving metal reactivity, always refer back to their positions in the reactivity series to determine the likelihood of a reaction. Remember that no signs of a reaction, such as a change in color or a deposit forming, indicate that the metals are 'deciding' to maintain the status quo due to their inherent reactivity.