Question

Select the most dilute solution a.A solution made by dissolving 60g of sodium hydroxide in 2000cm cubed b.A solution made by dissolving 40 g of sodium hydroxide in 1000 cm cubed of solution. c.A solution made by dissolving 10 g of sodium hydroxide in 250 cm cubed of solution. d.A solution made by dissolving 20 g of sodium hydroxide in 500 cm3 of solution.

Answer 1

Answer:

A, a solution made by dissolving 60g of sodium hydroxide in 2000cm³

Explanation:

Concentration = no. of moles / volume (in dm³)

1 dm³ = 1000cm³

no. of moles = mass / molar mass

molar mass of NaOH = 23.0+16.0+1.0 = 40 g/mol

Let's find the concentration of each of the solutions:

A:

= 60/40 /2

= 0.75 mol/dm³

B:

= 40/40 /1

= 1 mol/dm³

C:

= 10/40 / 0.25

=1 mol/dm³

D:

= 20/40 / 0.5

= 1 mol/dm³

Since 0.75mol/dm³ is the lowest concentration out of 4, it is the most dilute.