Molarity is defined as the ratio of number of moles to the volume of solution in litres.
The mathematical expression is given as:
[tex]Molarity = \frac{Number of moles}{volume of solution in litres}[/tex]
Here, molarity is equal to 1.43 M and volume is equal to 785 mL.
Convert mL into L
As, 1 mL = 0.001 L
Thus, volume = [tex]785\times 0.001[/tex] = 0.785 L
Rearrange the formula of molarity in terms of number of moles:
[tex]Number of moles =molarity\times volume of solution in litres[/tex]
n = [tex]1.43 M \times 0.785 L [/tex]
= 1.12255 mole
Now, Number of moles = [tex]\frac{mass in g}{molar mass}[/tex]
Molar mass of potassium hydroxide = 56.10 g/mol
1.12255 mole = [tex]\frac{mass in g}{56.10 g/mol}[/tex]
mass in g = [tex]1.12255 mole\times 56.10 g/mol[/tex]
= 62.97 g
Hence, mass of [tex]KOH[/tex] = 62.97 g
