4. A large quantity of a reactant that precipitates solid gold from gold in solution was added to a large sample of ocean water, but only a trace amount of solid gold resulted after
filtering the mixture. What do you think could be the problem? Describe one of the reactants
as a limiting reagent in your answer.

a. 249.5 g/mol

b. 1.996 g

c. Measure 1.996 g of and dissolve in water until the volume is 400 ml

Explanation:

Molar mass is the sum of atomic masses of all the elements present.

Thus molar mass of = 1(63.5)+1(32)+4(16)+5(18) = 249.5 g/mol

Molarity of a solution is defined as the number of moles of solute dissolved per liter of the solution.

To calculate the number of moles for given molarity, we use the equation:

c. We need to measure 1.996 g of and dissolve it in water to make the volume 400 ml.