Question

How many moles of kno3 are required to make 0.50 liters of a 2.0 m solution of kno3?

Answer 1

Molarity is defined as the number of moles of solute dissolved in 1 L of solution. 
KNO₃ - 2.0 M this means that 2.0 moles of KNO₃ are in 1 L of solution.
If 1 L contains - 2.0 moles
then 0.50 L contains - 2 mol/L x 0.50 L = 1 mol
Therefore 1 mol of KNO₃ is in 0.50 L solution.

Answer 2

Answer:

1.0 moles of $KNO_3$ are required to make 0.50 liters of a 2.0 m solution of $KNO_3$.

Explanation:

$Molarity(M)=\frac{Moles(n)}{Volume(L)}$

$Moles (n)=Molarity(M)\times Volume (L)$

Moles of potassium nitrate = n

Volume of potassium nitrate solution = 0.50 L

Molarity of the potassium nitrate = 2.0 M

$n=2.0 M\times 0.50 L=1.0 mol$

1.0 moles of $KNO_3$ are required to make 0.50 liters of a 2.0 m solution of $KNO_3$.