Test on Evaporation and Boiling: Separation Techniques
Evaporation and Boiling: Separation Techniques Explained
Test: Evaporation and Boiling of Liquids
20 questions
Question 1: Evaporation can be used to prepare different water samples for comparison by recovering any dissolved solids.
A. Ano
B. Ne
Explanation: The study materials state, 'In the lab, we can use evaporation to recover solids that have been dissolved in a solution by heating to dryness.' This process separates dissolved solids from the liquid, making it possible to compare the amounts or types of solids in different water samples, as implied by photo E and question 7.
Question 2: Is heating to dryness not a method used in the lab to recover solids dissolved in a solution?
A. Ano
B. Ne
Explanation: The study materials state: "In the lab, we can use evaporation to recover solids that have been dissolved in a solution by heating to dryness.", indicating that it is indeed a method for this purpose.
Question 3: The formation of stalactites and stalagmites involves the water solution reaching its boiling point.
A. Ano
B. Ne
Explanation: Stalactites and stalagmites form because each drop of water from the solution evaporates, leaving behind solid material. The study materials state that evaporation can happen at any temperature and does not require the liquid to reach its boiling point.
Question 4: When a liquid evaporates from a solution, the solids that were dissolved in it are left behind.
A. Ano
B. Ne
Explanation: The study materials state: 'During evaporation of a solution, the liquid turns into a gas which escapes into the air. The evaporating liquid leaves behind the solids that were dissolved in it.' This directly supports the statement that dissolved solids are left behind when a liquid evaporates from a solution.
Question 5: Under the same conditions, water and ethanol boil at the same temperature.
A. Ano
B. Ne
Explanation: Different liquids have different boiling points. Water boils at 100 °C and ethanol boils at about 78 °C under the same conditions, meaning they do not boil at the same temperature.