contestada

Read the statement.

Some amount of water is evaporated from a 2.0 L, 0.2 M NaI solution, to from a 1.0 L solution. The molar mass of NaI is 150 g/mol.

What is the final concentration of NaI solution in?

30 g/L
15 g/L
60 g/L
45 g/L

Respuesta :

Answer:

60 g/L is the final concentration of NaI solution .

Explanation:

Molarity of NaI solution before evaporation =[tex]M_1= 0.2 M[/tex]

Volume of NaI solution before evaporation =[tex]V_1= 2.0 L[/tex]

Molarity of NaI solution after evaporation =[tex]M_2= ?[/tex]

Volume of NaI solution after evaporation =[tex]V_2= 1.0 L[/tex]

[tex]M_1V_1=M_2V_2[/tex] ( dilution)

[tex]M_2=\frac{M_1V_1}{V_2}=\frac{0.2 M\times 2.0 L}{1.0 L}=0.4 M[/tex]

Molar mass of NaI = 150 g/mol

Concentration of NaI after evaporation :

0.4 M × 150 g/mol = 60 g/L

60 g/L is the final concentration of NaI solution .