Question

Cheese is a colloidal solution of:

• A. Solid in solid
• B. Liquid in solid
• C. Solid in liquid
• D. Gas in solid

Hint:

Colloidal solutions can have different phases of matter, such as liquid dispersed in solid, like in cheese.

Answer 1

The Correct Option is B

Cheese is a colloidal solution of: 

• Option 1: Solid in solid - This refers to a solid dispersion in another solid, like alloys or some kinds of metals. This is not the correct answer for cheese.
• Option 2: Liquid in solid - This is the correct answer. Cheese is a colloidal solution where a liquid (like water or milk proteins) is dispersed in a solid matrix (such as casein protein). This type of colloid is called a gel.
• Option 3: Solid in liquid - This refers to a solid dispersed in a liquid, like a suspension, which does not describe the structure of cheese.
• Option 4: Gas in solid - This describes foams and is not applicable to cheese, which does not primarily consist of a gas dispersed in a solid.

Explanation:

Cheese is classified as a colloidal solution where the liquid is dispersed within a solid, making it a gel-like substance. This is typical of cheese's structure, where liquid components are suspended within the solid protein matrix.

Answer 2

Cheese is being classified by its physical state combination. Check each option against cheese's actual structure.

1. Solid in solid: this would need one solid dispersed within another solid, like certain alloys, but cheese contains a liquid component too, so this does not fully describe it.
2. Liquid in solid: cheese is a gel-like structure where liquid, mainly water and fat, is trapped and held within a solid protein network formed mostly of casein. That liquid-within-solid structure matches cheese directly.
3. Solid in liquid: this describes something more fluid overall, with solid particles dispersed in a liquid medium, unlike cheese, which holds its own shape as a solid block.
4. Gas in solid: this describes something like foam trapped in a solid, such as bread or cork, not the liquid-holding structure of cheese.

Cheese traps liquid within a solid protein network, so it fits liquid dispersed in solid.

So the correct answer is liquid in solid.