Limit tests

Which of the following best describes the reaction between chloride ions (Cl⁻) and silver nitrate (AgNO₃) in an aqueous solution?

• Formation of a white precipitate of silver chloride (AgCl)

• Formation of a yellow precipitate of silver chloride (AgCl)

• Release of chlorine gas with effervescence

• Formation of a colorless solution with no visible change

Phenol red has a color change range from pH 6.8 (yellow) to pH 8.4 (violet). What color would it appear at pH 4?

• Violet

• Orange

• Yellow

• Red

When Mordant Black 11 forms a complex with alkali metals, which color is produced?

• Blue

• Violet

• Yellow

• Green

What is the main feature of sodium edetate (EDTA)?

• Acts as a strong acid

• Enhances metal ion concentration in solutions

• Functions as a reducing agent

• Forms stable complexes with metal ions

In the limit test for bromide, what color does the indicator turn to after bromination?

• Yellow

• Red

• Blue

• Violet