Question

Need little help pls

Answer 1

0.354 molal

Step-by-step explanation:

The molarity (M) or the concentration of a solution is defined as the number of moles of a compound in the solution per liter of solution (mol/L), whereas molality, is defined as the number of moles of a compound in the solution per kg of the compound (mol/kg).

Given that the density of the solution is 1.202 g/mL, which is equivalent to 1.202 kg/L. Since the prefix mili- denotes a factor of one thousandth (
`10^(-3)` ) and kilo- denotes a factor of one thousand (
`{10}^3` ),

`1.202 \ (g)/(mL) \ = \ 1.202 \ (g)/((10^(-3)) L) \ = \ 1.202 \ \frac{{10}^3g}{L} \ = \ 1.202 \ (kg)/(L)`.

To calculate the corresponding molality of the solution, the formula

`Molality \ (mol/kg) \ = \ (Molarity \ (mol/L))/(Density \ (kg/L))` is used.

Therefore,

`Molality \ = \ (0.426 \ mol/L)/(1.202 \ kg/L) \ = \ 0.354 \ mol/kg \ \ (3 \ s.f.)`