If a hydrate of the formula decomposes when heated to produce HCl, what change would you expect to occur when a piece of blue litmus paper is held in the path of the vapor released? [Litmus paper is paper impregnated with an acid-base indicator that is blue in the presence of base and red in the presence of acid.]
So if the hydrate gives off HCl (an acid), what color will that turn the paper?
It would turn red
because HCl id acidic
To determine the change that would occur when a piece of blue litmus paper is held in the path of the vapor released during the decomposition of a hydrate, we need to understand the chemical reaction that takes place and the behavior of litmus paper towards acids and bases.
1. Chemical reaction: In this case, the hydrate decomposes to produce HCl. The chemical equation for the reaction can be represented as:
Hydrate → HCl + water
2. Behavior of litmus paper: Litmus paper is an acid-base indicator that changes color based on the acidity or basicity of a substance. Blue litmus paper is blue in the presence of bases and remains blue when exposed to neutral or acidic substances.
Based on the information above, we can determine what change would be expected when the blue litmus paper is held in the path of the vapor released:
Since HCl is a strong acid, it will easily dissociate in water to produce hydrogen ions (H+) which will turn the litmus paper red. Therefore, when the vapor released from the decomposition of the hydrate reaches the blue litmus paper, the litmus paper will turn red.
So, the expected change when a piece of blue litmus paper is held in the path of the vapor released would be a color change from blue to red, indicating the presence of an acidic substance (HCl).