You need to make an aqueous solution of 0.187 M nickel(II) iodide for an experiment in lab, using a 300 mL volumetric flask. How much solid nickel(II) iodide should you add?

17.53 g

Explanation:

The chemical formula of nickel (II) iodide is NiI₂. Its molar mass (MM) can be calculated from the molar mass of its chemical elements:

MM(NiI₂) = 58.7 g/mol + (2 x 126.9 g/mol)= 312.5 g/mol

Given the following data:

M = 0.187 M = 0.187 mol/L

V= 300 mL = 0.3 L

We calculate the mass of NiI₂ as the product of the molarity of the solution (M), the molar mass (MM) and the volume:

mass = M x MM x V = (312.5 g/mol) x (0.187 mol/L) x 0.3 L = 17.53 g

Therefore, we have to add 17.53 grams of solid nickel(II) iodideto prepare the solution.

number of molecules / avogadro's number * molecule molecular = mass

explanation:

we define a gram-molecular weight as the mass of one mole of any element or compound. a mole contains avogadro's number of units (molecules) –  

6.022

x

10

23

. so, dividing the number of molecules by avogadro's number gives us the number of moles. multiplying that by the molecular weight gives us the mass. from the periodic table we find the gram-molecular weight of u to be238 and of f to be19. so,  

u

f

6

will have a gram-molecular weight of 352g.

since electrons are negative the answer is neagtaive