Question

Given the densities of the following pure liquids, what volume of each is necessary to make 250 mL of a 350 mM solution? a. Ethanol - 0.789 g/cm? b. Acetone -0.791 g/cm c. Formic acid - 1.220 g/cm3 d. tert-Butylamine - 0.696 g/cm?

Answer 1

(a) The volume of ethanol liquid needed are, 2.4 L

(b) The volume of ethanol liquid needed are, 1.9 L

(c) The volume of ethanol liquid needed are, 1.6 L

(d) The volume of ethanol liquid needed are, 1.7 L

Explanation : Given,

Volume of solution = 250 mL = 0.250 L (1 l = 1000 mL)

Concentration of solution = 350 mM = 0.350 M (1 mM = 0.001 M)

First we have to calculate the moles of solution.

`\text{Moles of solution}=\text{Concentration of solution}* \text{Volume of solution}=0.350M* 0.250L=0.0875mole`

(a) For ethanol liquid :

To we have to calculate the mass of ethanol.

`\text{Mass of ethanol}=\frac{\text{Moles}}{\text{Molar mass of ethanol}}=(0.0875mole)/(46g/mole)=0.0019g`

Now we have to calculate the volume of ethanol.

`Volume=(Mass)/(Density)=(0.0019g)/(0.789g/cm^3)=0.0024cm^3=0.0024mL=2.4L`

(b) For acetone liquid :

To we have to calculate the mass of acetone.

`\text{Mass of acetone}=\frac{\text{Moles}}{\text{Molar mass of acetone}}=(0.0875mole)/(58g/mole)=0.0015g`

Now we have to calculate the volume of acetone.

`Volume=(Mass)/(Density)=(0.0015g)/(0.791g/cm^3)=0.0019cm^3=0.0019mL=1.9L`

(c) For formic acid liquid :

To we have to calculate the mass of formic acid.

`\text{Mass of formic acid}=\frac{\text{Moles}}{\text{Molar mass of formic acid}}=(0.0875mole)/(46g/mole)=0.0019g`

Now we have to calculate the volume of formic acid.

`Volume=(Mass)/(Density)=(0.0019g)/(1.220g/cm^3)=0.0016cm^3=0.0016mL=1.6L`

(d) For tert-Butylamine liquid :

To we have to calculate the mass of tert-Butylamine.

`\text{Mass of tert-Butylamine}=\frac{\text{Moles}}{\text{Molar mass of tert-Butylamine}}=(0.0875mole)/(73g/mole)=0.0012g`

Now we have to calculate the volume of tert-Butylamine.

`Volume=(Mass)/(Density)=(0.0012g)/(0.696g/cm^3)=0.0017cm^3=0.0017mL=1.7L`