Question

Find out concentration of solution in %w/w if 100 gram Na2Co3 is dissolved in 900 g water ?

Answer 1

Answer:

As we know that,

Density=VolumeMass

Given:-

Density of solution =1.0816gm/mL

Volume of solution =100mL

∴1.0816=100Mass of solution

⇒Mass of solution=108.16g

Mass of solute (Na2CO3)=8.653g

Therefore,

Mass of solvent =108.16−8.653=99.507g

Molecular mass of Na2CO3=83g

As we know that,

No. of moles =Mol. massGiven mass

∴ No. of moles of Na2CO3=838.653=0.104 mol

Now,

As we know that,

Molarity =Volume of solution(in L)No. of moles of solute

Therefore,

Molarity =1000.104×1000=1.04M

Again, as we know that,

Molality =Mass of solution(in Kg)No. of moles of solute

Therefore,

Molality =99.5070.104

Explanation:

l hope it will help you

Answer 2

Explanation:

%w/w = mass of solute/mass of solution x 100

= mass of solute/mass of solute

+ x 100

mass of solvent

Putting the values in the formula:

= 100 /100+900 x 100

= 100/1000 x 100

= 0.1 x 100

= 10

Therefore, the %w/w = 10g