Problem 110 - A Complete Resource Book in Chemistry for JEE Main

Question

SnO can be prepared by (1) boiling a stannous chloride solution with \(\mathrm{Na}_{2} \mathrm{CO}_{3}\) (2) heating tin hydroxide in air (3) heating tin oxalate \(\left(\mathrm{SnC}_{2} \mathrm{O}_{4}\right)\) in absence of air (a) 1 and 2 (b) 2 and 3 (c) 1,2 and 3 (d) 1 and 3

Step-by-Step Solution

Answer

The correct answer is (c) 1, 2, and 3.

Step 1: Analyze Reaction 1

Boiling a stannous chloride solution with \( \text{Na}_2\text{CO}_3 \) results in the formation of tin (II) oxide, \( \text{SnO} \). This is because \( \text{Na}_2\text{CO}_3 \) acts as a precipitant, forming \( \text{Sn(OH)}_2 \), which upon heating, decomposes to \( \text{SnO} \). Therefore, reaction 1 can prepare SnO.

Step 2: Analyze Reaction 2

Heating tin hydroxide, \( \text{Sn(OH)}_2 \), in air leads to the removal of water forming \( \text{SnO} \), since the hydroxide dehydrates upon heating. Thus, reaction 2 is also a valid method of preparing \( \text{SnO} \).

Step 3: Analyze Reaction 3

Heating tin oxalate \( (\text{SnC}_2\text{O}_4) \) in the absence of air decomposes it into \( \text{SnO} \) and carbon dioxide gas, \( \text{CO}_2 \). This reaction occurs because the oxalate decomposes to form the oxide and releases \( \text{CO}_2 \) at high temperatures. Hence, reaction 3 can also be used to prepare \( \text{SnO} \).

Step 4: Evaluate Options

Option (c) is correct as it includes reactions 1, 2, and 3, all of which can independently produce \( \text{SnO} \). Other options do not include all applicable reactions.

Key Concepts

Chemical Reaction Analysis

Chemical reaction analysis is about understanding what happens during a chemical reaction. It's like being a detective.
You need to identify the reactants, the products, and the changes they undergo.
In preparing SnO, three reactions can be analyzed. - **Reaction 1**: Involves boiling stannous chloride with sodium carbonate. - **Reaction 2**: This involves heating tin hydroxide. - **Reaction 3**: Consists of heating tin oxalate without air. By analyzing these reactions, we determine whether they can produce tin(II) oxide (SnO). Understanding these reactions involves predicting products, balancing equations, and considering reaction conditions. A solid grasp of reaction analysis is fundamental to chemistry.
It ensures you can predict and verify the outcomes of various chemical changes.

Decomposition Reactions

Decomposition reactions involve breaking down a compound into two or more simpler substances.
They often require energy in the form of heat or electricity to occur.
In the context of preparing SnO, decomposition plays a crucial role. - **Tin Hydroxide to SnO**: Heating tin hydroxide leads to water loss, resulting in tin(II) oxide. - **Tin Oxalate to SnO**: Decomposing tin oxalate yields SnO and carbon dioxide. This is typical for oxalates, which often release carbon dioxide when heated. The decomposition of these compounds carefully controlled in the absence or presence of air varies.
It affects their conditions and products. These reactions showcase how elements rearrange themselves simply by changing conditions like temperature.

Precipitation Reactions

Precipitation reactions occur when two solutions combine to form an insoluble product, known as a precipitate.
In reaction one, this concept is seen when stannous chloride meets sodium carbonate, resulting in Sn(OH)₂.
When heated, Sn(OH)₂ decomposes into SnO. Understanding precipitation is essential. Here's why: - **Formation**: Identifies conditions under which a solid forms from a solution. - **Separation**: Useful in processes like purification or treatment of solutions. Precipitation helps isolate a particular component. This technique is invaluable for creating pure substances, like SnO, from a mixture or solution.

Tin Compounds Chemistry

Tin compounds exhibit a wide range of chemistry due to their ability to form various compounds with different elements.
SnO is one such compound formed under specific conditions. Understanding tin compounds enables predictions about their reactions and stability. - **Reactivity**: Tin tends to form oxides, chlorides, hydroxides, and oxalates due to its +2 and +4 oxidation states. - **Diverse Uses**: Tin compounds can be used in coatings, pigments, and ceramics, highlighting the importance of mastering their chemistry. The preparation of SnO involves understanding tin's interaction with other elements and conditions.
Mastery over the chemistry of tin allows chemists to design processes for production or application effectively.