Problem 2 - A Complete Resource Book in Chemistry for JEE Main

Question

The beans are cooked sooner in a pressure cooker, because (a) boiling point increase with increasing pressure (b) boiling point decrease with increasing pressure (c) extra pressure of pressure cooker, softens the beans (d) internal energy is not lost while cooking in pressure cooker.

Step-by-Step Solution

Answer

The beans cook sooner because (a) boiling point increase with increasing pressure.

Step 1: Understand Pressure Cooking

Cooking in a pressure cooker involves sealing the pot to trap steam, which increases the pressure inside the pot. This raised pressure impacts how food cooks.

Step 2: Boiling Point and Pressure Relationship

When pressure increases, the boiling point of water also increases. This means the water remains in a liquid state at a higher temperature than usual, enabling faster cooking.

Step 3: Analyzing the Options

Options (a) and (b) discuss boiling points: (a) suggests the boiling point increases with pressure (which is correct), and (b) suggests it decreases. Option (c) mentions pressure usefulness without explanation. Option (d) describes energy retention incorrectly.

Step 4: Correct Answer Identification

Given that increasing pressure raises the boiling point, enabling higher cooking temperatures within the cooker, the correct option is (a). This allows beans to cook faster.

Key Concepts

Boiling Point and Pressure Relationship

When cooking, you might notice water boils at 100°C under normal conditions. However, this changes when pressure increases. The relationship between boiling point and pressure is quite interesting. As pressure is increased inside a sealed environment, like a pressure cooker, the boiling point of water also increases.

This is because the added pressure exerts force on the liquid's surface, requiring more heat energy to convert the liquid phase into vapor. Therefore, water can remain a liquid at much higher temperatures than it does at standard atmospheric pressure. This is crucial when you're trying to cook food faster, ensuring it reaches higher temperatures without drying out.

• Increased pressure leads to a higher boiling point.
• Allows water to stay liquid at temperatures above 100°C.
• Paves the way for efficient and faster cooking.

Pressure Cooking

Pressure cooking is a method that uses a sealed pot to create high-pressure steam inside. This technique has become popular because it allows foods to be cooked faster than using conventional methods. In a pressure cooker, steam is trapped, and the pressure builds up rapidly until it reaches a set level.

This increased pressure raises the water's boiling point. Consequently, food cooks at a higher temperature, allowing it to cook thoroughly in a shorter time. Pressure cooking is particularly beneficial for beans, tough cuts of meat, and other foods that usually require long cooking times.

• Makes use of trapped steam to increase pressure.
• Raises the boiling point, cooking food at higher temperatures.
• Speeds up cooking time, especially effective for dense foods.

Cooking Techniques

Understanding different cooking techniques can greatly impact your culinary results. Pressure cooking is one such technique. It is valued for its ability to reduce cooking time while preserving nutrients that might otherwise be lost through prolonged heat exposure. This method relies on the relationship between temperature, pressure, and vapor, enabling quick cooking without compromising flavor or texture.

While pressure cooking is efficient, it is also crucial to know when and how to apply various other techniques. Experimenting with a blend of methods, such as steaming, boiling, and baking, can lead to exciting flavors and textures. However, remember that each method has its specific purpose and culinary benefits. Including pressure cooking in your repertoire enhances overall cooking efficiency.

• Offers a diverse approach to cooking with multiple techniques.
• Aids in nutrient preservation through efficient cooking.
• Fosters culinary creativity by combining different techniques.