She dissolves a 10.0mg sample in enough water to make 30.0ml of solution. the osmotic pressure of the solution is 0.340torr at 25c. a). what is the molar mass of the gene fragment? b). if the solution density is 0.997g/ml, what is the freezing point for this aqueous solution?

(a)The molar mass of the gene fragment is 18220.071g/mol = 18.22 kg/mol

(b)The freezing point for the aqueous solution is C

Explanation:

The osmotic pressure (π) is given by the following equation:

= Concentration of solution

R = universal gas constant = 62.364

T = temperature

Weight of solute = w = 10.0 mg

Let the molecular weight of the solute be m g/mol.

Concentration =

m = 18220.071g/mol

Therefore, the molar mass of the gene fragment is 18220.071g/mol = 18.22 kg/mol

m is the molality of the solution.

m = mol/kg

= C

The freezing point for the aqueous solution is C

the enthalpy of formation of water is given as -285.8kj/mol, which states that the enthalpy of formation is negative.

negative enthalpy of formation indicates that the heat is released during the reaction process. the heat is released from reaction to the surroundings the enthalpy is expressed with a negative sign with the energy given out in the reaction process.

the formation of water takes place by giving out heat which is -285.8 kj/mol.