A solution of phosphoric acid was made by dissolving 10.0 g H3PO4 in 100.0 mL water. The resulting volume was 104 mL. Calculate the density, mole fraction, molarity, and molality of the solution. Assume water has a density of 1.00 g/cm3 .

Respuesta :

Answer:

density is 1.057 g/mL

mole fraction is 0.0180

molarity is 0.98 mol/L

mole fraction is 0.0180

Explanation:

Given data

acid mass = 10 g

water volume = 100 mL

total volume = 104 mL

density = 1 g/cm³

to find out

the density, mole fraction, molarity, and molality

solution

first we calculate the density that is = total mass g / volume of solution mL

total mass = mass of H3PO4 + water  mass

so water mass = density x volume

water mass = 100 ml x 1.0  g/cm3

water mass = 100 g  

so total mass  = 110.00 g

so that

density = total mass g / volume of solution mL

density = 110 / 104 = 1.057 g/mL

now we calculate no of moles in solvent i.e = mass  H2O / mlar mass H2O

no of moles in solvent = 100/18.015 = 5.55 moles

and no of moles in solute i.e = mass of H3PO4 / mlar mass in H3PO4

moles in solute i.e = 10/ 97.994 = 0.102 moles

so total moles is  5.55  + 0.102 = 5.652 moes

so now mole fraction = no of moles in solute / total moes

mole fraction = 5.55 / 5.65

mole fraction is 0.0180

now we calculate first

mole fraction in solute and solvent that is

mole fraction in solute = no of moles in solute/ total moles

mole fraction in solute = 0.102 /5.65

mole fraction in solute is 0.0180

and mole fraction in solvent that = no of moles in solvent/ total moles

mole fraction in solvent that = 5.55/ 5.65

mole fraction in solvent that is 0.982

so molarity = no of moles of solute / volume

molarity = 0.102/0.104

molarity is 0.98 mol/L

and molality  is = no of moles of solute / mass

molality = 0.102 / 100

molality  is  1.02 mol/kg

The density of the solution is defined as the mass per unit volume. The density, mole fraction, molarity, and molality of the solution are 1.057 g/mL,0.0180,0.98 mol/L,1.02 mol/kg respectively.

What is density?

Density is defined as the mass per unit volume. Its unit is kg/m³.it is used to find how the material is dense.

The given data in the problem are ;

Mass of acid= 10 g

volume of water = 100 mL

total volume given = 104 mL

Density of water  = 1 g/cm³

(a) Density

[tex]\rm{ Density \;of \;solution=\frac{Total \;mass }{Total \;volume} }[/tex]

Total mass = mass of H₃PO₄ + mass of water

Mass of water = density of water × volume of water

Mass of water([tex]\rm m_w[/tex])=  1 g/cm³×100 mL

Mass of water([tex]\rm m_w[/tex])=100 g.

Total mass = mass of H₃PO₄ + mass of water

Total mass= 10g+100g= 110 g

[tex]\rm{ Density \;of \;solution=\frac{Total \;mass }{Total \;volume} }[/tex]

[tex]\rm{ Density \;of \;solution=\frac{110}{104} }\;gm/mL[/tex]

[tex]\rm{ Density \;of \;solution=1.057 gm/ml[/tex]

Hence the density of the solution will be 1.057 gm/mL.

(b)Mole fraction

Mole of solution = Mole of solvent + Mole of solute

[tex]\rm{ Mass \;of\; solvent = \frac{Mass\;of \;H_2O }{Moler \;Mass\; of\;H_2O} }\\\\\rm{ Mass \;of\; solvent = \frac{100 }{18.015}\;mole\\\\[/tex]

[tex]\rm{ Mass \;of\; solvent = 5.55 \;mole[/tex]

[tex]\rm{ Mass \;of\; solute = \frac{Mass\;of \;H_3PO_4 }{Moler \;Mass\; of \;H_3PO_4 } }\\\\\rm{ Mass \;of\; solute = \frac{10 }{97.9944}\;mole\\\\[/tex]

[tex]\rm{ Mass \;of\; solvent =0.102 \; mole[/tex]

Moles of solution = Mole of solvent + Mole of solute

Moles of solution = 5.55+0.102= 5.652 moles.

[tex]\rm Mole \; fraction= \frac{Mole\; of \;solute }{Mole \;of \;solution} \\\\\rm Mole \; fraction= \frac{5.55 }{5.65}}\\\\\rm Mole \; fraction= 0.0180[/tex]

Hence the mole fraction of the solution is 0.0180

(c)  Molarity

[tex]\rm{Molarity= \frac{no \;of\; moles \;of \;solute}{volume} }\\\\\rm{Molarity= \frac{0.102}{0.104} }\\\\\rm{Molarity= 0.98 mol/lit}[/tex]

Hence the molarity of the solution will be 0.98 mol/lit.

(d) Molality

[tex]\rm Molality = \frac{No \;of \;moles \;of \;solute}{mass} \\\\\rm{Molality= \frac{0.102}{100} } \\\\\rm{Molarity=1.02 mol/kg }[/tex]

Hence the molality of the solution will be 1.02 mol/kg.

Hence the density, mole fraction, molarity, and molality of the solution will be is 1.057 g/mL,0.0180,0.98 mol/L,1.02 mol/kg respectively.

To learn more about the density refer to the link

https://brainly.com/question/952755

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