Solution A contains 7 g/L of `MgCl_(2)` and solution B contains 7 g/L of NaCl. At room temperature, the osmotic pressure of :

Options

A. solution A is greater than B
B. both have same osmotic pressure
C. solution B is greater than A
D. can't determine

Answer

C

Explanation

`7 gL^(-)MgCl_(2) = (7)/(24+7)mol L^(-1)`
`= (7)/(95)mol L^(-1)=(7xx3)/(95)mol L^(-1)` of ions
`= 0.22 mol L^(-1)` of ions
`7gL^(-1) NaCl = (7)/(23+35.5) mol L^(-1)`
`= (7)/(58.5)mol L^(-1) = (7xx2)/(58.5)mol L^(-1)` of ions
`= 0.24 mol L^(-1)` of ions
Since concentration of ions in NaCl is greater, NaCl solution (Solution B) will have greater osmotic pressure.