Which of the following statements is not correct? (A) TiCl4 is a colourless compound.
(B) (Cr(NH3)c)]Cl3 is a coloured compound.
(C) K3[VF] is a colourless compound.
(D) [Cu(NCCH3)4][BF4] is a colourless compound.

the density of gold = 19.3 g/cm3

the relation between density and mass and volume is

density = mass / volume

given :

mass of gold = 13 g

density = 13g / volume = 19.3

volume = 13 /19.3 = 0.67 cm^3

thus volume of gold nugget = 0.67 cm^3

the formula mass of a molecule or a compound is the sum of the atomic weights of the atoms in its empirical formula

(that's what i know about formula mass)