Question

Which dye is obtained from plants? (a) indigo (b) orange-I (c) aniline yellow (d) none

Short answer

Indigo is obtained from plants.

Step-by-step solution

Identifying the Given Choices

We are presented with four options: (a) indigo, (b) orange-I, (c) aniline yellow, and (d) none. Our task is to determine which of these dyes is derived from plants.

Understanding Plant-derived Dyes

Plant-derived dyes are natural dyes obtained directly from plant sources without any synthetic process. These include various colors from roots, leaves, bark, fruits, and seeds.

Analyzing Option A

Indigo is a well-known dye extracted from the leaves of plants like Indigofera tinctoria. Historically and traditionally, it has been used as a natural dye, particularly for dyeing fabrics blue.

Analyzing Option B

Orange-I is a synthetic dye commonly used in textiles. It does not originate from any plant source. It is chemically synthesized and not categorized as a natural dye.

Analyzing Option C

Aniline yellow is an artificial dye derived from aniline, a synthetic compound. Therefore, it is not obtained from natural, plant-based materials.

Final Conclusion

Based on our analysis, indigo is the only dye mentioned in the options that is sourced from plants. Therefore, option (a) indigo is the correct answer.

Key concepts

Indigo Dye

Indigo dye is one of the oldest dyes used by humans, cherished for its deep blue color. This dye is derived from the leaves of certain plants, predominantly the Indigofera tinctoria. The process of extracting indigo dye from plants involves fermenting the leaves to transform the precursor compound indican into indigo.

Once processed, indigo dye is primarily used in the textile industry to color fabrics, most famously denim jeans. It owes its popularity not only to its rich, vibrant hue but also to its ability to bind effectively to textile fibers, resulting in a long-lasting color.

• Historical significance in ancient cultures
• Desirable for its vivid and durable color
• Eco-friendly compared to some synthetic dyes

Natural Dyes

Natural dyes are colorants derived from natural resources such as plants, minerals, and even animals. Unlike synthetic dyes, which are made through chemical processes, natural dyes are extracted using traditional techniques like boiling, fermentation, or steeping.

Natural dyes offer a wide spectrum of colors and are environmentally friendly as they are biodegradable. However, they can sometimes require more time and effort to work with compared to synthetic dyes.

• Extracted from roots, flowers, seeds, and leaves
• Safe for the environment and often non-toxic
• Used historically and culturally across the world

Synthetic Dyes

Synthetic dyes are human-made through chemical synthesis, offering a wide range of colors. These dyes were developed as a response to the limitations and challenges of natural dyes, such as consistency, variety, and production scale.

The synthesis process involves chemical reactions that produce large quantities of dye, often more vibrant and easily repeatable in consistency than their natural counterparts. However, synthetic dyes can have environmental impacts if not managed properly, due to the chemicals involved in their production.

• Common in the textile industry for their vibrancy
• Can be cheaper and more consistent in color
• Need careful handling to minimize environmental harm