Calculate the molarity of each of the following solutions.70.8g C2H60 in 2.51L of solution
70.8 g divided by the molecular weight of C2H6O.
Put that answer over 2.51L
since Molarity is moles/liter you can setup a proportion:
answer/2.51 = ???/1.00
To calculate the molarity of a solution, you need to know the number of moles of solute and the volume of solution in liters.
To find the number of moles of solute:
1. Determine the molar mass of the solute.
- In this case, the solute is C2H6O, which includes 2 carbon atoms (C), 6 hydrogen atoms (H), and 1 oxygen atom (O).
- The atomic masses are C = 12.01 g/mol, H = 1.01 g/mol, and O = 16.00 g/mol.
- The molar mass of C2H6O can be calculated as follows:
Molar mass of C2H6O = (2 × atomic mass of C) + (6 × atomic mass of H) + atomic mass of O
= (2 × 12.01) + (6 × 1.01) + 16.00
= 24.02 + 6.06 + 16.00
= 46.08 g/mol
2. Convert the given mass of solute (70.8 g) to moles.
- Moles of solute = mass of solute / molar mass
= 70.8 g / 46.08 g/mol
≈ 1.5378 mol
Next, find the volume of the solution (in liters):
The given volume is 2.51 L.
Finally, use the formula for molarity:
Molarity = moles of solute / volume of solution (in liters)
= 1.5378 mol / 2.51 L
Calculating this expression gives the molarity of the solution.