Question

20 gm of salt are dissolved in 80 grams of water the concentration of the solution will be​

Answer 1

20 gram of salt are dissolved in 80 gram of water.

we have to find the concentration of the solution.

solution : Therefore are so many methods to find concentration of solution. for instance, mass percent, part per million, mass/volume percent , volume percent, molarity and Molality .

here from data we can only find Molality.

because Molality = no of moles of solute/mass of solvent in kg

here mass of salt = 20g

molar mass of salt , NaCl = 58.5 g/mol

so, molar mass of salt = 20/58.5

mass of solvent ( water) = 80g = 80/1000 kg

now Molality = (20/58.5)/(80/1000)

= (20 × 1000)/(58.5 × 80)

= 4.27 molal

Therefore the concentration of solution is 4.27 molal.

Answer 2

Answer:

20%

Formula:

MaoS (mass of solute) "MoSo"

(Mass of solvent)

MaoS/ (MaoS+MoSo) × 100

Solution:

20g/(20g+80ml)×100

= (20g/100)×100

= 0.2×100

=20

= add percentage (20%)

Q:Why is there a hundred?

A: because it is solving for the "percentage" per-cent (100)