Question

Calculate the molarity of a solution containing
14 gm of KOH in 750 ml of solution.​

Answer 1

$\huge{\underline{\underline{Answer\::-}}}$

$\underline{\underline{Given\::-}}$

Mass of KOH = 14 g

Volume of solution = 750 ml or 0.75 liter

$\underline{\underline{Solution\::-}}$

♦ As molarity = $\frac{moles \: of \: solution}{liters \:of \: solution}$

♦ Then to find out Number of moles of solution

• We have to get molar mass of KOH

• We have to divide given mass by molar mass to find out Number of moles present

>> Mass of KOH

•As per mole mass of

Hydrogen = 1 gram

Oxygen = 16 gram

Potassium = 39 gram

>>Then molar mass

= 1(39) + 1(1) + 1(16)

= 39 + 1 + 16

= 56 gram

>> Moles of KOH

= $\frac{mass}{molecular \:mass}$

= $\dfrac{14}{56}$

= $\dfrac{1}{4}$ moles

♦ Molarity of KOH

= $\dfrac{ \dfrac{1}{4} }{0.75}$

= $\dfrac{1}{4 \times 0.75}$

= $\dfrac{1}{3}$

= 0.333... Molar