Using the molarity equation, calculate how many grams of salt you need in order to make 80ml of a 2m solution (mw = 58.44g/mole)?

9.35g

Explanation:

The molarity equation establishes that:

So, we have information about molarity (2M) and volume (80 ml=0.08 l), with that, we can find the moles of solute:

The  mathematical equation that establishes the relationship between molar weight, mass and moles is:

We have MW (58.44g/mole) and n (0.16 mol), and we need to find m (grams of salt needed) to solve the problem:

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 answer is option a.