Question

Zinc on reaction with steam liberates ______ gas.

Short answer

Answer: Hydrogen gas (H2) is released when zinc reacts with steam.

Step-by-step solution

Write down the balanced chemical equation

When zinc reacts with steam, the balanced chemical equation for the reaction is: Zn (s) + H2O (g) → ZnO (s) + H2 (g) Here, zinc (Zn) reacts with steam (H2O) to form zinc oxide (ZnO) and release a certain gas.

Identify the gas produced

In the balanced chemical equation from Step 1, we can see that the gas produced is hydrogen gas (H2). This means that when zinc reacts with steam, hydrogen gas is released. So, the answer to the given exercise is that zinc on reaction with steam liberates hydrogen gas.

Key concepts

Zinc and Steam Reaction

When zinc reacts with steam, a fascinating chemical transformation occurs. This process involves the combination of zinc (a metal) with water in its gaseous form, known as steam. The initial phase consists of heating zinc to a temperature where steam can react with it effectively. In this reaction, zinc displaces or replaces the hydrogen atoms present in the steam.
This interaction results in the formation of zinc oxide (ZnO) and the liberation of hydrogen gas (H2). This process is an example of a single displacement reaction because one element, zinc, is taking the place of another, hydrogen, in a compound. Understanding this type of reaction is beneficial because it showcases how elements can interchange places in such reactions and release different products.

Balancing Chemical Equations

Balancing chemical equations is a crucial skill in chemistry that ensures the law of conservation of mass is maintained. This law states that mass cannot be created or destroyed in a chemical reaction. Thus, the number of atoms for each element on the reactant side must equal the number of atoms on the product side.
To balance a chemical equation, one must adjust the coefficients (the numbers in front of molecules) to ensure equilibrium. In the reaction between zinc and steam, the balanced equation is:
\[ \text{Zn (s) + H2O (g) → ZnO (s) + H2 (g)} \]
Note that there is one zinc atom, one oxygen atom, and two hydrogen atoms on both sides of the equation. This balance ensures that the same quantity of each element present before the reaction is present afterward as well. Balancing equations may require trial and error but is a foundational tool in predicting and understanding chemical reactions.

Gas Production in Reactions

In many chemical reactions, gases are liberated as a product, highlighting both their transformative and energetic nature. The production of gas is often associated with physical observations like bubbling or a change in pressure, but it's crucial to comprehend the theoretical aspect of gas production too.
When zinc reacts with steam, hydrogen gas is produced. Recognizing the element hydrogen in its gaseous state is important due to its widespread presence in reactions and its role as a fuel. Producing gas like hydrogen can have various applications, from energy production to industrial manufacturing.
In chemical equations, the liberation of gas is often indicated by an upward arrow (↑) beside the gaseous product or an explicit mention of its state, like (g). Understanding how and why gases form can explain many real-world phenomena and is vital in chemical engineering, environmental science, and other fields.