Answer:
28g/ dm³
0.5 M
Explanation:
1dm³= 1000cm³
Let's convert the volume to cm³.
Volume of solution
= 200cm³
= (200÷1000) dm³
= 0.2 dm³
Concentration in g/dm³ means the amount of solute, KOH, in 1 dm³ of solution.
In 0.2 dm³, there is 5.6g of KOH.
Thus in 1 dm³, amount of KOH
= 5.6 ÷0.2
= 28g
Concentration in g/dm³ is 28g/dm³.
Molarity is a concentration unit. It is the number of moles of solvent in 1 L or 1dm³ of solution. Since we have already found the mass of KOH in 1dm³ of solution, we will use dm³.
1dm³ ----- 28g of KOH
moles= mass ÷mr
Molecular mass of KOH
= 39 +16 +1
= 56
1dm³ ----- 28 ÷56= 0.5 moles of KOH
Thus, concentration in molarity is 0.5M.
(Unit for molarity is M)
