A sample of insoluble chlorides was prepared for analysis using aqueous solutions of lead (II) nitrate, silver nitrate, and mercury (I) nitrate with concentrated hydrochloric acid. To a portion of this sample, aqueous NH3 was added followed by a nitric acid solution, and a white precipitate was formed. Required:
a. What ion is present in this sample (i. e. what ion is responsible for the formation of the precipitate)?
b. What is the net ionic equation for the formation of the first precipitate of this ion (i. e. ion formed when concentrated hydrochloric acid was added to the solutions), including states of matter?

the electrical  conductivity  of asolution  of an electrolyte is measured by determining the resistance of thesolution  between two flat or cylindrical electrodes separated by a fixed distance.

what is the question?

a 20-cm-long, cylindrical graphite (pure carbon) rod is inserted into an oxidizing atmosphere at 1145 k and 1.013 x 105 pa pressure. the oxidizing process is limited by the diffu- sion of oxygen counterflow to the carbon monoxide that is formed on the cylindrical surface.

atomic mass = 39

number of neutrons = 20

number of protons= 19

electronic configuration = 1s2 2s2 2p6 3s2 3p6 4s1

the number of electron in first shell = 2

number of electrons in n=3 shell = 8