Answer:
Option B. 3.0 M
Explanation:
From the question given above, the following data were obtained:
Volume of solution = 3.0 L
Mole of MgCl₂ = 9 moles
Molarity =?
Molarity can simply be defined as the mole of solute per unit litre of the solution. Mathematically, it can be expressed as:
Molarity = mole of solute /Volume of solution
With the above formula, we can obtain the molarity of the solution as follow:
Volume of solution = 3.0 L
Mole of MgCl₂ = 9 moles
Molarity =?
Molarity = mole of solute /Volume of solution
Molarity = 9 / 3
Molarity = 3 mol/L = 3.0 M
Thus, the molarity of the solution is 3 M
And a water molecule, this is called a dehydration synthesis. when 2 molecule combine, a water molecule leave.
Answer:
3.56x10^24 molecules
Explanation:
The following data were obtained from the question:
Mass of Na2SO4 = 840g
Molar Mass of Na2SO4 = (23 x2) + 32 + (16x4) =46 + 12 + 64 = 142g/mol
From Avogadro's hypothesis, 1mole of any substance contains 6.02x10^23 molecules. This also gives that 1mole of Na2SO4 contains 6.02x10^23 molecules.
If 1 mole (i.e 142g) contains 6.02x10^23 molecules,
Therefore, 840g of Na2SO4 will contain = (840 x 6.02x10^23)/142 = 3.56x10^24 molecules
