Neoid
Answered

A salt has a mass of 20 grams placed in 250 grams of water. What is the percentage by mass? Please Give The Formula And The Solution Thanks:)

Sagot :

Bellalesseid
I'm going to solve it using the GRESA form.

G : m solute = 20 grams; solvent = 250 grams

R : percent by mass

E : % bm = [tex] \frac{m solute}{m solution} [/tex] x 100; solution = solute + solvent

S : % bm = [tex] \frac{m solute}{m solution} [/tex] x 100
               = [tex] \frac{20}{250} x 100[/tex]
               = 0.08 x 100
               = 8

A : 8%
Jeremiaid
Asked:  What is the percentage by mass? 

Percentage by Mass of Solute (salt) 

       =                       [tex] \frac{mass of solute}{mass of solution} [/tex]
          
       =                        [tex] \frac{20g}{20g + 250g} [/tex]
       =                        [tex] \frac{20g}{270g} [/tex]
      =                         7.40% (rounded off to the nearest hundredths)

Percentage by Mass of Solvent (water)

     =                           [tex] \frac{mass of solvent}{mass of solution} [/tex]
     =                           [tex] \frac{250g}{250g + 20g} [/tex]
     =                           [tex] \frac{250g}{270g} [/tex]
     =                           92. 60% (rounded off to the nearest hundredths)