Question

When a nickel salt is heated with boric anhydride, brown coloured bead is formed which is due to the formation of (a) \(\mathrm{NiO}\) (b) \(\mathrm{Ni}\left(\mathrm{BO}_{2}\right)_{2}\) (c) \(\mathrm{Ni}_{2} \mathrm{~B}_{4} \mathrm{O}_{7}\) (d) None of these

Short answer

The brown bead is due to the formation of \(\mathrm{Ni}\left(\mathrm{BO}_{2}\right)_{2}\).

Step-by-step solution

Understand the Problem

We're tasked with identifying the product formed when nickel salt is combined with boric anhydride and heated, resulting in a brown-colored bead. We have multiple choice options to consider.

Consider Known Reactions

The reaction involves nickel salt and boric anhydride. A well-known bead test reaction involves a borax and a metal in which, when heated, forms a colored bead attributed to the metal borate. Here, we're focusing on identifying the compound that fits the description (brown color).

Analyze Color Changes

In the bead test, different metal ions yield specific colored beads. Nickel, when heated with boric anhydride, typically results in specific types of nickel borate compounds, which can be responsible for the bead color, such as a brown bead.

Evaluate Options

Evaluate the given options:- \ \(\mathrm{NiO}\) typically forms a black or gray bead, not aligning with the brown description.- \ \(\mathrm{Ni}\left(\mathrm{BO}_{2}\right)_{2}\) is a nickel borate and is known to form characteristics aligned with the problem.- \ \(\mathrm{Ni}_{2} \mathrm{~B}_{4} \mathrm{O}_{7}\) is an alternate form of nickel borate but doesn't usually match the description as well as \(\mathrm{Ni}\left(\mathrm{BO}_{2}\right)_{2}\).

Choose the Best Answer

Considering all the information, the brown-colored bead formed is most likely due to the formation of \(\mathrm{Ni}\left(\mathrm{BO}_{2}\right)_{2}\), a type of nickel borate known for corresponding color properties.

Key concepts

Boric Anhydride Reaction

Reactions involving boric anhydride are fascinating. Boric anhydride, also known as boron trioxide ( 2O_3), is a glassy solid that plays a crucial role in various chemical reactions. When boric anhydride is combined with other substances, such as nickel salt, it can lead to the formation of interesting compounds through a high-temperature process.
One notable reaction is when boric anhydride interacts with metals, like nickel, during a heating process. This is part of the bead test chemistry, a technique where boric anhydride serves as a flux, promoting the formation of metal borates. As a result, a colored bead is produced, which is indicative of the metal identity involved in the reaction. In our case, reacting nickel salt with boric anhydride leads to the formation of brown bead, highlighting the small but crucial role boric anhydride plays in revealing the metallic identity through visual cues.

Bead Test Chemistry

Among the various classical techniques chemistry offers, bead test chemistry holds a special place. It involves a simple but informative method to identify metal ions through color changes. When you heat a metal salt with a flux, like boric anhydride, these materials melt and react to form colored beads. These beads provide visible clues on the type of metal ion present.
The interaction of metals with fluxes follows a straightforward principle: different metals will produce distinct colors upon heating. For instance, when nickel salt interacts with boric anhydride, a brown bead emerges, indicating the formation of a nickel borate compound. It's a perfect real-world application of chemistry basics, where a simple test can reveal much about the interacting substances. This method assists chemists by offering a quick, visual confirmation of metal presence and identity without needing complex instrumentation.

Colorimetric Analysis in Chemistry

Colorimetric analysis is a technique used in chemistry to determine the concentration of a chemical element or compound in a solution with the aid of color. It's like reading the story of a chemical interaction through its color changes. This method leverages the Beer-Lambert Law, which relates the absorbance of light to the properties of the material it's passing through.
During reactions like the bead test, color becomes an essential indicator. Chemists utilize colorimetric analysis by observing the colors of beads to infer the type and concentration of metal ions present. For example, the formation of a brown bead when nickel salts react with boric anhydride is not just a visual cue but also a precise indicator of the nickel's presence and its reacting form. It highlights how visually engaging and scientifically rigorous chemistry can be, making it easier to identify and analyze elements quickly.

Inorganic Chemistry Reactions

Inorganic chemistry focuses on reactions involving minerals, metals, and other non-organic compounds. These reactions are the backbone of countless industrial and laboratory processes. Understanding how metals interact with various non-metals or oxides is a key focus of inorganic chemistry.
For example, the reaction between nickel salts and boric anhydride illustrates the dynamic interactions in inorganic chemistry. When these substances are heated together, they undergo a thermal reaction that produces new compounds like nickel borates. The visual output, such as the formation of a brown bead, is an exciting outcome of these complex reactions.
By studying these interactions, scientists can predict behaviors, design new materials, or even develop industrial processes that exploit these insightful reactions. It opens up a world of possibilities that reach into everything from materials science to environmental studies.