What is the mass/volume percent of a solution with 75g of na2co3 dissolved in 20.0 g of water?
11%

9.3 %

30%

7.5%

percent by mass = 79%

Explanation:

Data Given:

mass of solute (Na₂CO₃) = 75 g

mass of solvent ( water ) = 20 g

mass percent of solution = ?

Solution:

Formula used to find percent by mass

                          mass of solute / mass of solution x 100 . . . . . . (1)

first we have to find mass of solution

              mass of solution = mass of solute + mass of Solvent . . . . (2)

put values in equation 2

             mass of solution = 75 g + 20 g

             mass of solution = 95 g

Now,

put values in equation 1

 Percent by mass = mass of solute / mass of solution x 100

 Percent by mass = 75 g / 95 g x 100

 Percent by mass = 79 %

so,

The percent of the solution by mass = 79%

***Note:

The same work can be used for the other values too i.e. if you have 20 g of solute and 75 g solvent.

in chemistry, adhesion and cohesion are attractive forces that exist between molecules. they hold the molecules together from each other. they are different in that adhesive force exists between molecules of different substance while cohesive force happens between molecules of same substance.

adhesion between water and glass causes water molecules at the edge of water and glass interface to climb up the wall in a narrow glass tube. this is called capillary action. cohesion is what gives glass its shape and causes water to form a droplet.