The mass of potassium hydroxide required to make 300.ocm3 of 0.4 moldm-3 solution is {KOH = 56.0}

A.

26.88g

B.

13.44g

C.

6.72g

D.

3.36g

Correct answer is C

300cm3 of 0.4moldm3

1000cm3 contains 0.4mole

300cm3 will contain \(\frac{300 \times 0.4}{1000}\)

= 0.12mole

Number of moles = \(\frac{Mass}{\text {Molecular mass}}\)

Mass = number of moles x m.mass

= 0.12 x 56 = 6.72g