Can someone help me with question 3 pls I’m am clueless

Using a value of ksp = 1.8 x 10-2 for the reaction pbcl2 pb+2(aq) + 2cl -(aq). if the value of ksp was determined to be only 1.2 x 10-2: too much solid has dissolved. additional precipitate is forming. the solution is unsaturated. the ions are now combining to reduce their concentrations.

What substance has a mass of 9.5g and volume of 2.1cm^3

Suppose you wanted to make 100 grams of water. what is the molar mass of water (h2o)?