Answer:
Having a specific set of possible values
Measure the brightness of a star through two filters and compare the ratio of red to blue light.
Answer: Option (4) is the correct answer.
Explanation:
When sulfuric acid reacts with calcium hydroxide then it results in the formation of calcium sulfate and water.
The chemical reaction for the same will be as follows.

Thus, we can conclude that
salt is produced when sulfuric acid and calcium hydroxide react completely.
Methylene chloride is less dense than water