Red color in acidic solutions and blue color in basic solutions.
Litmus paper turns red in acidic solutions and blue in basic solutions due to a change in the concentration of hydronium ions (H3O+) or hydroxide ions (OH-) which alter the color of the dye in the litmus paper. Bases, by definition, are substances that release hydroxide ions in water, causing the litmus paper to turn blue.
The paper turn to a blue color.
The color will be blue.
It will remain blue.
Ammonia is a basic (alkaline) substance that can dissociate in water to produce hydroxide ions (OH⁻). When damp red litmus paper comes into contact with ammonia, the hydroxide ions interact with the dye in the litmus paper, causing a color change from red to blue. This indicates the presence of a basic solution, as blue litmus paper would remain blue in the presence of a base.
Any acid or base should do the trick.Any compound with excess hydrogen ions (H+) or excess hydroxide ions (OH-). Also, any compound that absorbs hydrogen ions (H+) or hydroxide ions (OH-).
It is the hydroxide ion (OH-) in sodium hydroxide (NaOH) that causes red litmus to turn blue. The hydroxide ion is a strong base and can accept protons from the acidic red litmus dye, resulting in a color change.
Dry HCl gas does not change the color of dry litmus paper because it does not produce H+ ions in the absence of water. Litmus paper changes color when it comes into contact with acidic or basic solutions that release H+ or OH- ions. Dry HCl gas cannot dissociate into H+ ions without water to facilitate the reaction.
When a strong base is dissolved in water, it forms hydroxide ions (OH-) in solution. These hydroxide ions are responsible for the basic properties of the solution, such as the ability to neutralize acids and turn litmus paper blue.
Litmus paper, other types of pH paper, phenolphtalein, etc.
Water provides H+/ OH- ions for the dry gas(to be tested with litmus) to show its acidic/alkaline nature.
Dry ammonia is neutral to litmus because it does not produce any protons (H+) or hydroxide ions (OH-) when dissolved in water. Litmus paper changes color in the presence of these ions, so if a substance does not produce them when dissolved, it will not affect the color of litmus paper.