The results of the experiment are shown below.

Investigation.

A chemical contractor is suspected of pouring dangerous chemicals into the river system and polluting the local water supply. Heavy metals appeared in the water and caused serious health problems in the local community. In trying to identify the metals present, a study was undertaken. Samples of water from three different rivers were collected and tested with the following chemicals.

What are the possible metals present in each river?

White precipitates are very common. A sample of water from a nearby river was tested with a chloride solution. A white precipitate is formed. The locals suspect that lead is present. Suggest further tests that can be carried out and what results can be expected to show the presence or absence of lead.

A Jewelry store was robbed of silver valued at one million dollars. The silver was dissolved by chemical means and sold. A suspect was arrested and his clothing tested. Describe two tests that can be conducted to see if silver metal is present on the suspect's clothing.
The chemicals and their formulae are shown below.