If 12.8 g lead(II) sulfate (303.3 g/mol) precipitates when excess potassium chloride is added to 1.65 L of a water sample, what is molar concentration of Pb2+ in the sample?

Explanation:

Hello,

In this case, the undergoing chemical reaction is:

In such a way, since all the lead (II) is converted due to the excess of potassium chloride, the moles of lead (II) in the sample are computed from the mass of lead (II) sulfate:

Thus, since volume of the solution is 1.65 due to the fact that the addition of the reactants is not enough to significantly modify the reaction's volume, the resulting molar concentration of the lead (II) ions is:

Regards.

just did the assignment and the answer was #1 +2 n

metals are good conductor of electricity. it has free electrons on their surface. according to electron pool theory, each atom present in a metal crystal losses all of its valence electron and as a result a pool of free is form. these pool of electrons are free to move and   conduct electricity easily   while making metal as good conductor.

the correct answer is a. the ability of electrons to flow throughout the metal.

if it's not useful, feel free to report for mistake in answer.