Question

140 g of KCl is dissolved in 600 mL of water. What is the molarity?

Answer 1

u=mol/L

1.88/0.600L

=3.13u

140*1molKCL/75gKCL

=1.88molkCL

600/1*1LH2O/1000ml H2O

=0.600L h2o

Answer 2

$\textsf{\underline {\Large {MOLARITY}}}$ :

$\textsf{\underline {Solution}}$ :

$\boxed{ \mathsf{\dfrac{Molarity,\: M \:=\:Number\:of\:moles\:of\:solute\:(\:KCl\:) \:*\:1000}{Volume \:of\:solution\:(\:ml\:) }}}$

Given, Mass of KCl ( Potassium Chloride) ( Solute ) = 140 g

Volume of water ( solution ) = 600 mL

Moles of KCl $\mathsf{n_{\tiny{KCl}}}$ = $\mathsf{\dfrac{Given \:Mass\:of\:KCl} {Molar\:Mass\:of\:KCl}}$

Moles of KCl $\mathsf{n_{\tiny{KCl}}}$ = $\mathsf{\dfrac{140}{39\:+\:35.5}}$

Moles of KCl $\mathsf{n_{\tiny{KCl}}}$ = $\mathsf{\dfrac{140}{74.5}}$

Moles of KCl $\mathsf{n_{\tiny{KCl}}}$ = $\mathsf{1.879\: mol}$

Molarity, M = $\mathsf{\dfrac{Number\:of\:moles\:of\:solute\:(\:KCl\:) \:*\:1000}{Volume \:of\:solution}}$

Molarity, M = $\mathsf{\dfrac{1.879\:*\:1000}{600}}$

➡️ $\boxed{ \mathsf{Molarity, M\:=\:3.131\:M\:or\:mol{L}^{-1}}}$