Question

помогите с утверждениями по химии,какие из них верные?чистые вещества имеют постоянный составсмесь поваренной соли с речным песком можно разделить с помощью добавления воды и последующей фильтрования и выпаривания

Answer 1

по моему оба утверждения верные

Answer 2

Pure substances have a constant composition.

This statement is true. Pure substances are made up of only one type of particle and have a fixed composition. This means that the ratio of the different elements or compounds in a pure substance remains the same regardless of the amount or source of the substance. For example, pure water (H2O) will always have a fixed ratio of two hydrogen atoms to one oxygen atom, regardless of the source or quantity of water. [[1]]

A mixture of table salt and river sand can be separated by adding water and subsequent filtration and evaporation.

This statement is true. A mixture of table salt (sodium chloride, NaCl) and river sand can be separated by adding water and using the processes of filtration and evaporation. Here's how the separation process works:

1. Add water to the mixture of salt and sand. The salt will dissolve in water, while the sand will remain insoluble. 2. Stir the mixture to ensure that the salt dissolves completely in the water. 3. Use a filter to separate the sand from the saltwater solution. The sand particles will be retained by the filter, while the saltwater solution will pass through. 4. Collect the saltwater solution in a container. 5. Heat the saltwater solution to evaporate the water. As the water evaporates, the salt will start to crystallize and can be collected.

By following these steps, the salt can be separated from the sand, as the salt dissolves in water and can be recovered through evaporation, while the sand remains behind as a solid. [[2]]