The osmotic pressure of a $1 \ M$ solution at $27^{\circ}C$ is $(R = 0.082 \ L \ atm \ K^{-1} \ mol^{-1})$: (in $atm$)

What is a "semi-permeable membrane"?

Assertion : If red blood cells were removed from the body and placed in pure water,pressure inside the cells increases.
Reason : The concentration of salt content in the cells increases.

Which of the following statements regarding isotonic solutions is $NOT$ correct?

Calculate the molar mass of a solute when $4 \ g$ of it is dissolved in $1 \ dm^3$ of solvent,having an osmotic pressure of $2 \ atm$ at $300 \ K$. $[R = 0.082 \ dm^3 \ atm \ K^{-1} \ mol^{-1}]$

$A$ $5\%(w/v)$ solution of sucrose is isotonic with a $1\%(w/v)$ solution of substance '$A$'. What is the molar mass of substance '$A$'?