g When aqueous solutions of and are mixed, a solid forms. Determine the mass of solid formed when 140.7 mL of 0.1000 M is mixed with an excess of an aqueous solution of .

The question is incomplete, the complete question is:

When aqueous solutions of NaCl and are mixed, a solid forms. Determine the mass of solid formed when 140.7 mL of 0.1000 M NaCl is mixed with an excess of an aqueous solution of

The mass of lead chloride produced is 1.96 g

Explanation:

Molarity is defined as the amount of solute expressed in the number of moles present per liter of solution. The units of molarity are mol/L. The formula used to calculate molarity:

.....(1)

Given values:

Molarity of NaCl = 0.1000 M

Volume of the solution = 140.7 mL

Putting values in equation 1, we get:

The chemical equation for the reaction of NaCl and lead nitrate follows:

By the stoichiometry of the reaction:

If 2 moles of NaCl produces 1 mole of lead chloride

So, 0.01407 moles of NaCl will produce = of lead chloride

The number of moles is defined as the ratio of the mass of a substance to its molar mass.

The equation used is:

......(2)

Molar mass of lead chloride = 278.1 g/mol

Plugging values in equation 2:

Hence, the mass of lead chloride produced is 1.96 g

your answer is a. the enthalpy of formation for a pure element in its standard state is always positive.