Chapter 10: Problem 57
Which on heating with NaOII solution gives inflammable gas? (1) \(\mathrm{Zn}\) (2) \(\mathrm{P}\) (3) \(\mathrm{S} \mathrm{i}\) (4) \(\Lambda 11\)
Short Answer
Step by step solution
Key Concepts
These are the key concepts you need to understand to accurately answer the question.
Reactivity of Elements
Zinc (Zn) and lithium (Li) are two elements that react with sodium hydroxide (NaOH). Zinc reacts to form zinc hydroxide and hydrogen gas, a moderately reactive process. The chemical equation is \(\text{Zn} + 2\text{NaOH} \rightarrow \text{Zn(OH)}\text{2} + \text{H}_2\).
On the other hand, lithium reacts much more vigorously. Lithium's reaction with water, even in a sodium hydroxide solution, is highly exothermic, producing lithium hydroxide and releasing hydrogen gas. The reaction is: \(\text{Li} + \text{H}_2\text{O} \rightarrow \text{LiOH} + \text{H}_2\).
This explains why lithium consistently produces inflammable hydrogen gas, making it more reactive than zinc, phosphorus (P), and silicon (Si) in these conditions.
Production of Hydrogen Gas
When a metal like zinc or lithium reacts with sodium hydroxide, it displaces hydrogen atoms from water molecules, forming hydrogen gas. For zinc, the equation is: \(\text{Zn} + 2\text{NaOH} \rightarrow \text{Zn(OH)}\text{2} + \text{H}_2\).
Similarly, lithium reacts with water in the NaOH solution to produce hydrogen gas: \(\text{Li} + \text{H}_2\text{O} \rightarrow \text{LiOH} + \text{H}_2\).
This production is significant because hydrogen gas is a clean energy source. However, it is also highly flammable, requiring careful handling and storage. Recognizing which elements easily produce hydrogen gas helps scientists and engineers harness this property safely and effectively.
Properties of Metals
- Conductivity: Metals like copper and aluminum are excellent conductors of electricity and heat.
- Malleability: Many metals can be hammered or rolled into thin sheets without breaking.
- Ductility: Metals can be drawn into wires, which is particularly useful in electrical wiring and cabling.
- Reactivity: As highlighted in this exercise, metals can react with acids, bases, and water to produce gases and other compounds.
When it comes to reactivity, metals like lithium are highly reactive, especially with water and bases, leading to the production of hydrogen gas. This differs from less reactive metals such as phosphorus and silicon, which do not react readily or produce gases under similar conditions.
Understanding the properties of metals, including reactivity, is crucial in fields like chemistry, material science, and engineering. This knowledge allows for the appropriate selection of metals for specific applications, ensuring safety and efficacy in their use.