The student placed 10 ml of pbcl2 (saturated solution) in the test tube and added a pinch of nacl. a white precipitate of pbcl2 formed. how will this affect the concentration of pb+2?

Concentration of decreases

Explanation:

In a saturated solution of , the following solubility equilibrium exist-

Now, NaCl contains common ion . Therefore, concentration of increases in solution.

But, at a particular temperature, equilibrium constant remain constant. Therefore to keep equilibrium constant same will reacts with excess to decrease concentration of .

Therefore concentration of decreases.

Note: Equilibrium constant for the above equilibrium=

explanation:

let the different atoms be x and y. each with four protons and same mass will be represented as follows.

mass number is number of protons + number of neutrons.

            and  

since, it is given that one has a negative charge while the other is neutral. therefore, there will be increase in number of protons and the atom will be represented as follows.

according to periodic table, mass number of beryllium is 9 and it has atomic number 4 so, the atoms will be and .  

the protons and neutrons will be located inside the nucleus whereas the electrons will be revolving around the nucleus.