4. Given the density of Au is 19.3 g/cm3, determine the mass of gold in an ingot having a volume of 0.015 m3.

A chemist measures the amount of chlorine gas produced during an experiment. She finds that 721. g of chlorine gas is produced. Calculate the number of moles of chlorine gas produced. Round your answer to 3  significant digits.

Q1. The net potential energy between two adjacent ions, EN, is represented by A В EN pn where En is the net energy in Joule (J), A and B are constants with values of 1.436 J.m and 7.32 × 106 J.nm°, r is the interatomic distance between the two ions in nanometer (nm), and n is a positive number with a value of 8. Using these information, determine the equilibrium spacing between the two ions in nanometer (nm).

Mr. Auric Goldfinger, criminal mastermind, intends to smuggle several tons of gold across international borders by disguising it as lumps of iron ore. He commands his engineer minions to form the gold into little spheres with a diameter of exactly 8 cm and paint them black. However, his chief engineer points out that customs officials will surely notice the unusual weight of the "iron ore" if the balls are made of solid gold (density 19.3 g/cm"). He suggests forming the gold into hollow balls One of the balls of fake instead (see sketch at right), so that the fake "iron ore" has the same density as real iron ore (5.15 g/cm'). "iron ore," sliced in half. Calculate the required thickness of the walls of each hollow lump of "iron ore." Be sure your answer has a unit symbol, if necessary, and round it to 2 significant digits.