When a solution containing dissolved elements and compounds is left to evaporate, what typically happens to the dissolved substances after the water has evaporated?

• A. They remain as solid residues in the container.
• B. They evaporate along with the water.
• C. They react with water to form new compounds.
• D. They decompose into different elements.

Answer: (A)

Verified step by step guidance

1. Understand that when a solution contains dissolved substances (solutes) in a solvent like water, the solutes are dispersed at the molecular or ionic level within the solvent.
2. Recognize that evaporation involves the phase change of the solvent (water) from liquid to gas, leaving behind any non-volatile substances dissolved in it.
3. Recall that most dissolved solids do not evaporate at the temperature and pressure conditions typical for water evaporation, so they cannot leave the solution as gases.
4. Therefore, as the water evaporates, the concentration of dissolved substances increases until they can no longer remain dissolved and begin to precipitate out as solid residues.
5. Conclude that after complete evaporation of the water, the dissolved substances typically remain as solid residues in the container.