General Lab Questions: (8 points) 5. A) What is the main problem with precipitating strontium ions from the town's water using phosphate? Can you think of any reasons that your results might not be accurate?

1) high pH is required

2) other ions are precipitated along with the strontium ions

Explanation:

According to the solubility rules all phosphates are insoluble except those of sodium, potassium, and ammonium. This implies that strontium phosphate is insoluble in water. This explains why strontium ions can be precipitated from drinking water supply using phosphate. The main problem with the precipitation of strontium using phosphate is that it usually requires a high pH as the precipitation occurs under very alkaline conditions.

The main reason why the results may not be accurate is that other ions are precipitated along with the strontium such as calcium ions and magnesium ions. This may lead to inaccurate determination of the amount of strontium ions present.

- lead + phosphoric acid = hydrogen + lead(ii) phosphate

b.

the accuracy of the data.