P.S. Semester 1 Exam '24-'25

Front

What is the purpose of an eye wash station in a laboratory?

Back

An eye wash station is used to rinse the eyes in case of exposure to harmful substances, ensuring safety and preventing injury.

Front

What does pH measure in a solution?

Back

pH measures the acidity or basicity of a solution on a scale of 0-14, where 7 is neutral, below 7 is acidic, and above 7 is basic.

Front

Define an element in chemistry.

Back

An element is a natural or synthetic material that cannot be broken down into simpler substances by ordinary means, classified as a metal, metalloid, or nonmetal.

Front

What is a physical change? Give an example.

Back

A physical change is any change in size, shape, form, or state of matter where the identity of the matter remains the same. Example: boiling water.

Front

What is a solvent?

Back

A solvent is the substance that does the dissolving in a solution, such as water.

Front

What is the difference between a chemical change and a physical change?

Back

A chemical change results in the formation of new substances with different properties, while a physical change does not alter the identity of the substance.

Front

What are indicators in chemistry?

Back

Indicators are substances that change color in response to changes in pH, helping to determine the acidity or basicity of a solution.

Front

What is the definition of a mixture?

Back

A mixture is a combination of two or more substances where each retains its own properties and can be separated by physical means.

Front

What is the role of a solute in a solution?

Back

A solute is the substance that is dissolved in a solvent to form a solution.

Front

What is the significance of the fire blanket in a laboratory?

Back

A fire blanket is used to smother small fires or to wrap around a person whose clothing is on fire, providing a safety measure in emergencies.