Explanation:
To calculate the concentration of solute, we use the equation for osmotic pressure, which is:
[tex]\pi=icRT[/tex]
where,
[tex]\pi[/tex] = osmotic pressure of the solution =
i = Van't hoff factor =
c = concentration of solute =
R = Gas constant = [tex]0.0820\text{ L atm }mol^{-1}K^{-1}[/tex]
T = temperature of the solution = T
1) For 1 M [tex]MgCl_2[/tex]:
[tex]MgCl_2\rightarrow Mg^{2+}+2Cl^-[/tex]
i = 3
c = 1 M
[tex]\pi _1=3\times 1M \time RT=3RT[/tex]
2) For 1 M [tex]KCl[/tex]:
[tex]KCl\rightarrow K^{+}+Cl^-[/tex]
i = 2
c = M
[tex]\pi _2=2\times M \time RT=2RT[/tex]
3) For 2 M [tex]CH_3CH_2CH_2OH[/tex]:
i = 1 ( organic molecule)
c = 2 M
[tex]\pi _3=1\times 2M \time RT=2RT[/tex]
4) For 1 M [tex]C_{12}H_{22}O_{11}[/tex]:
i = 1 ( organic molecule)
c = 1 M
[tex]\pi _4=1\times 1M \time RT=1RT[/tex]
Osmotic pressures in decreasing order
[tex]\pi _1>\pi _2=\pi _3>\pi _4[/tex]
1 M [tex]MgCl_2[/tex]>1 M [tex]KCl[/tex]=2 M [tex]CH_3CH_2CH_2OH[/tex]>1 M [tex]C_{12}H_{22}O_{11}[/tex]