Integrated Science( First Year )

To clean a test tube, one should use a test tube brush. This tool is specifically designed to fit inside the narrow and cylindrical shape of a test tube, allowing for effective cleaning. Using a graduated cylinder or triple beam balance would not be suitable for cleaning purposes. Crucible tongs are used for holding and manipulating hot crucibles, not for cleaning test tubes. Therefore, the correct tool to use for cleaning a test tube is a test tube brush.

A funnel is used to transfer liquid to another bottle without spilling because it has a wide top opening that allows the liquid to be easily poured into the funnel. The narrow spout of the funnel helps to control the flow of the liquid and direct it into the narrow opening of the bottle, minimizing the chances of spillage.

Acid is a substance that can burn the skin and other materials. Acids are corrosive and have the ability to react with other substances, causing damage or destruction. When acids come into contact with the skin, they can cause burns and irritation. Additionally, acids can corrode or dissolve certain materials, such as metals or fabrics. Therefore, acid is the correct answer as it fits the description of a substance that can burn the skin and other materials.

Evaporation is the process by which a liquid changes into a gas. It occurs when the molecules of a liquid gain enough energy to overcome the forces of attraction between them and escape into the surrounding environment as vapor. During evaporation, the liquid's temperature decreases as the high-energy molecules leave, resulting in cooling. This process is commonly observed when water evaporates from a surface, such as when a puddle dries up or clothes dry after being hung out to air. Evaporation is an important part of the water cycle and plays a crucial role in weather patterns and the distribution of water on Earth.

When diluting an acid, it is important to always add the acid slowly to water. This is because adding water to acid can cause a violent reaction, splashing the acid and potentially causing harm. By adding the acid slowly to water, the reaction is less likely to be violent and the mixture can be stirred to ensure proper dilution. This method helps to minimize the risk of accidents and ensures safe handling of acids.

To get the mass of water, you would use the graduated cylinder. The graduated cylinder is a measuring device used to accurately measure the volume of liquids. By measuring the volume of water in the graduated cylinder, you can then use the density of water to calculate its mass.

The correct answer is "volume". Volume refers to the amount of space that matter occupies. It is a measure of the three-dimensional space that an object or substance occupies. In other words, it is the physical size of an object or the capacity of a container.

To measure the density of a liquid, you need to know its mass and volume. The apparatus that can help you determine both of these factors are a graduated cylinder (II) and a triple beam balance (III). A graduated cylinder can be used to measure the volume of the liquid, while a triple beam balance can be used to measure the mass of the liquid. Therefore, using both apparatus (II and III) will allow you to calculate the density accurately. The beaker (I) and test tube (IV) are not suitable for measuring volume or mass accurately, so they are not included in the correct answer.

When doing an experiment that involves heating or using fire, it is important to be ready with an apron. An apron provides protection for your clothing, preventing it from getting damaged or catching fire. It is a safety precaution that helps to minimize the risk of accidents or injuries while working with heat or fire.

The correct answer is "wear safety goggles and aprons at all times in the laboratory". This is incorrect because safety goggles and aprons should be worn at all times in the laboratory to protect against potential hazards.