Respuesta :
m(H₂O)=250 g=0.250 kg
m(NaOH)=20.0 g
M(NaOH)=40.0 g/mol
n(NaOH)=m(NaOH)/M(NaOH)
Cm=n(NaOH)/m(H₂O)
Cm=m(NaOH)/{M(NaOH)m(H₂O)}
Cm= 20.0/{40.0*0.250}=2 mol/kg
m(NaOH)=20.0 g
M(NaOH)=40.0 g/mol
n(NaOH)=m(NaOH)/M(NaOH)
Cm=n(NaOH)/m(H₂O)
Cm=m(NaOH)/{M(NaOH)m(H₂O)}
Cm= 20.0/{40.0*0.250}=2 mol/kg
Answer : The molality of a solution is, 2 mole/Kg
Explanation : Given,
Mass of solute (NaOH) = 20 g
Mass of solvent (water) = 250 g
Molar mass of NaOH = 40 g/mole
Molality : It is defined as the number of moles of solute present in one kilogram of solvent.
Formula used :
[tex]\text{Molality}=\frac{\text{Mass of }NaOH\times 1000}{\text{Molar mass of }NaOH\times \text{Mass of water}}[/tex]
Now put all the given values in this formula, we get the molality of a solution.
[tex]\text{Molality}=\frac{20g\times 1000}{40g/mole\times 250g}=2mole/Kg[/tex]
Therefore, the molality of a solution is, 2 mole/Kg
