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: Option C
Explanation
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