Mass of this substance = 9.928 g
Further explanation
Molarity is a way to express the concentration of the solution
Molarity shows the number of moles of solute in every 1 liter of solute or mmol in each ml of solution
[tex]\large{\boxed {\bold {M ~ = ~ \frac {n} {V}}}[/tex]
Where
M = Molarity
n = Number of moles of solute
V = Volume of solution
So to find the number of moles can be expressed as
[tex]\boxed{\bold{n=V\times M}}[/tex]
mol of substance -Lithium nitrite - LiNO₂ :
V = 250 ml = 0.25 L
M = 0.75 M
[tex]\tt n=0.25\times 0.75=0.1875[/tex]
So mass of this substance - LiNO₂ (MW=52,947 g/mol) :
[tex]\tt mass=mol\times MW\\\\mass=0.1875\times 52,947 g/mol\\\\mass=9.928~g[/tex]
