Question

For each of the following NaOH solutions, the volume of the solution and its molarity are given. Calculate the number of moles of NaOH present in each solution.

1.35 L solution, 0.300 M

0.800 L solution, 0.100 M

875 mL solution, 0.600 M

125 ml solution, 0.125 M

Answer 1

1)

volume , V = 1.35 L

use:

number of mol,

n = Molarity * Volume

= 0.3*1.35

= 0.405 mol

Answer: 0.405 mol

2)

volume , V = 0.8 L

use:

number of mol,

n = Molarity * Volume

= 0.1*0.8

= 8.00*10^-2 mol

Answer: 8.00*10^-2 mol

3)

volume , V = 8.75*10^2 mL

= 0.875 L

use:

number of mol,

n = Molarity * Volume

= 0.6*0.875

= 0.525 mol

Answer: 0.525 mol

4)

volume , V = 1.25*10^2 mL

= 0.125 L

use:

number of mol,

n = Molarity * Volume

= 0.125*0.125

= 1.562*10^-2 mol

Answer: 1.56*10^-2 mol