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El alcohol sanitario tiene una concentración de 96°lo que equivale a decir que es del 96% en volumen . Calcula para una botella de 250ml a) la concentración de la masa b)la molaridad y la molalidad c)la fracción molar de soluto d)¿que masa de HCL habrá en 25ml de disolución.
Accepted Answer
Here's a breakdown of the calculations for a 96% (v/v) alcohol solution in a 250mL bottle:
a) Concentration of the mass (mass/volume):
Assume the density of the alcohol is 0.789 g/mL (a typical value for ethanol)
Mass of alcohol = volume of alcohol
density of alcohol
Mass of alcohol = 250 mL
0.96
0.789 g/mL = 189.36 g
Concentration of the mass = 189.36 g / 250 mL = 0.757 g/mL
b) Molarity and Molality:
Molarity (M) = moles of solute / volume of solution (in L)
Molality (m) = moles of solute / mass of solvent (in kg)
To calculate these, we need the molecular weight of ethanol (C2H5OH), which is 46.07 g/mol.
Moles of ethanol = 189.36 g / 46.07 g/mol = 4.11 mol
Volume of solution = 250 mL = 0.25 L
Mass of solvent (water) = 250 mL
(1 - 0.96)
1 g/mL = 10 g = 0.01 kg
Molarity = 4.11 mol / 0.25 L = 16.44 M
Molality = 4.11 mol / 0.01 kg = 411 m
c) Fraction molar of solute:
Mole fraction of solute (χsolute) = moles of solute / (moles of solute + moles of solvent)
To find the moles of solvent (water), we need its mass (10 g) and molecular weight (18.015 g/mol):
Moles of water = 10 g / 18.015 g/mol = 0.555 mol
χethanol = 4.11 mol / (4.11 mol + 0.555 mol) = 0.882
d) Mass of HCl in 25 mL of solution:
You haven't provided information on the presence of HCl in the alcohol solution. Therefore, we can't calculate its mass in 25 mL. Please specify the concentration of HCl in the solution.
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