Astudent is given two clear solutions. one solution contained lead ions, pb2+ and the other solution contains chloride ions, cl-. when the two solutions are mixed, a clear solution with white powder at the bottom results. what has happen to cause this change?

A chemical change has occurred.

Explanation: A chemical change is a change which results when there is a change in the chemical composition of the atoms.

Chemical changes are accompanied by:

a) Change in color

b) Absorption or release of heat

c) formation of precipitates

d) production of gas

The white powder is precipitates of lead chloride which do not dissolve.

a is the correct answer

c is having 4 valence electrons and is bonded to three hydrogens and one sulphur atom, therefore, the number of bond pair is equal to four. as all the valence electrons are used in forming the bonds so, there is no lone pair left on carbon.

s is having 6 valence electrons and is bonded to one other sulfur atom and one carbon atom, therefore, the number of bond pair is equal to 2. as only two valence electrons are used in forming the bonds so, four electrons are left. therefore, two lone pairs are present on s.