The rock has a mass of 6g and a volume of 3cm3. What is the density of the rock?

2g/cm³

Explanation:

Given parameters:

Mass of rock  = 6g

Volume of rock  = 3cm³

Unknown:

Density of rock  = ?

Solution:

Density is the mass per given volume of a substance. It can be mathematically expressed as:

        Density  =  

 Insert the parameters and solve;

      Density  =   = 2g/cm³

the answer is either b or c

1. for the first question, we must find the mass of the anhydrous salt, mgso₄. the molar mass for mgso₄·7h₂o is 246.47 g/mol, while that of mgso₄ is 120.37 g/mol.7.834 g mgso₄·7h₂o * 1 mol mgso₄·7h₂o/246.47 g * 1 mol mgso₄/1 mol mgso₄·7h₂o * 20.37 g mgso₄/mol = 0.647 g mgso₄

2. mass of water = mass of sample - mass of anhydrous salemass of water = 7.834 - 0.647 = 7.19 gpercent water in hydrate = 7.19/7.834 * 100 = 91.74%