Salt and pH Meter

What is the primary indicator used in Mohr’s method of chloride determination?

• Phenolphthalein

• Methyl orange

• Potassium chromate

• Bromothymol blue

In Mohr titration, the appearance of which precipitate indicates the endpoint?

• White precipitate of AgCl

• Red-brown precipitate of Ag₂CrO₄

• Yellow precipitate of PbI₂

• Orange precipitate of Cr₂O₇²⁻

In the Mohr method, what happens at the endpoint of the titration?

• All potassium chromate reacts with chloride ions

• All silver ions precipitate as AgCl

• Excess silver ions react with potassium chromate to form a red complex

• All chloride ions turn into chromate ions

What is the main principle behind the working of a pH meter?

• It measures the temperature of the solution

• It calculates the mass of hydrogen ions

• It measures electrical voltage potential related to acidity or alkalinity

• It detects the color change in a solution

What role does the thin glass membrane play in a pH electrode?

• It prevents contamination of the sample

• It detects changes in temperature

• It allows H⁺ ions to pass through and create a measurable voltage

• It neutralizes the OH⁻ ions in the solution

What happens when the probe is placed in an alkaline solution?

• H⁺ ions enter the probe, creating a positive potential

• OH⁻ ions leave the probe, creating a neutral potential

• H⁺ ions migrate out of the probe, creating a negative potential

• The probe becomes impermeable to H⁺ ions