# Determining the Identity of Irregular Solids

• justinbaker
In summary, the conversation discusses a chemistry lab question about determining the identity of a soluble solid. The question specifically asks about determining the volume of an irregularly shaped solid that is soluble in water. The individual believes that they need to find the density, which involves measuring the mass and volume. However, they are unsure how to accurately measure the volume if the solid dissolves in water. They suggest using a liquid that the solid will not dissolve in to measure its volume.

#### justinbaker

well trying to help my little brother with some chem homework, and i believe i am just thinking too hard about this question

anyways its a whole chem lab thingy about the composition of pennies and one of the thinking questions is

Explain how you might determine the identity of an irregularly shaped solid that is soluble in water

now when it says "identity" I am assuming they are talking about density. mass/volume

so obviously we weigh the solid to get the mass

but if it dissolves in water, how are we supposed to get the volume?

is it as simple as putting the solid in a liquid that it will not dissolve in?

Yeah, it sounds as simple as putting it in a liquid it won't dissolve into measure its volume.

I would first like to clarify that the term "identity" in this context could refer to different properties of a substance, not just density. However, based on your understanding, I will provide a response.

To determine the identity of an irregularly shaped solid that is soluble in water, there are a few methods that could be used. The first method would be to measure the density of the solid. This can be done by measuring its mass and volume. As you mentioned, the mass can be obtained by weighing the solid on a balance. However, since the solid dissolves in water, we cannot directly measure its volume.

In this case, we can use the displacement method to determine the volume of the solid. This involves placing the solid in a graduated cylinder filled with a liquid that the solid will not dissolve in, such as a nonpolar liquid like oil. The volume of the liquid will increase, and the difference between the initial and final volume will be equal to the volume of the solid. This can then be used to calculate the density of the solid.

Alternatively, if the solid is not completely soluble in water, we can also use the method of filtration. This involves passing the solution of the solid and water through a filter, which will separate the insoluble solid from the soluble components. The mass of the solid collected on the filter can then be measured, and its density can be calculated.

In conclusion, determining the identity of an irregularly shaped solid that is soluble in water can be achieved by measuring its density, which involves obtaining its mass and volume. The volume can be determined using the displacement method or by filtering out the insoluble components.

## 1. What is the process for determining the identity of irregular solids?

The process for determining the identity of irregular solids involves measuring the dimensions of the solid using a ruler or caliper, calculating its volume and/or surface area, and comparing these values to known values of different solids.

## 2. Can the identity of an irregular solid be determined accurately?

Yes, with precise measurements and thorough calculations, the identity of an irregular solid can be determined accurately. However, there may be slight variations due to the irregular shape of the solid.

## 3. Are there any limitations when using this method to determine the identity of irregular solids?

Yes, there are limitations. This method may not work for extremely complex or asymmetrical solids, as it relies on comparing measurements to known values of regular solids. It also requires precise measurement tools and calculations, which may not always be available.

## 4. How does the density of an irregular solid affect its identity determination?

The density of an irregular solid can provide additional information in determining its identity. By measuring the mass and volume of the solid, its density can be calculated and compared to known densities of different solids, helping to narrow down the options for its identity.

## 5. Are there any alternative methods for determining the identity of irregular solids?

Yes, there are alternative methods such as using 3D scanning technology or creating a 3D model of the solid to compare to known shapes. These methods may be more accurate and efficient, but also may require specialized equipment and knowledge.