Question

Calculate the concentration in percent of 9.0g of salt in 100.0g of solution

Answer 1

Answer:

use the following ex to solve

EXAMPLE:

(a) If 25 moles of NaCl are present in 100 L of a solution wherein H2O is the solvent, then the concentration of the solution is

25

100

=

0.25

mol⋅L

−

1

.

(b) What is the molarity of a solution prepared by dissolving 15.0 g of sodium hydroxide in enough water to make a total of 225 mL of solution?

Solution

Calculate the number of moles of solute present.

Moles of NaOH = 15.0 g NaOH ×

1

mol NaOH

40.00

g NaOH

= 0.375 mol NaOH

Calculate the number of litres of solution present.

Volume = 225 mL ×

1

L

1000

mL

= 0.225 L soln

Divide the number of moles of solute by the number of litres of solution.

Molarity =

0.375

mol

0.225

L

= 1.67 mol/L

Answer 2

Answer:

9 ÷ 100 = 0.09

0.09 × 100 = 9%

Answer=9%