The heat of fusion of pure nitric oxide (no) is 2.30 kj/mol at its freezing point of -164 oc (when pressure is 1 atm). suppose you add 112 grams of a fully soluble, non-dissociating substance to 1000 g of nitric oxide. you measure the freezing point temperature of the solution to be 0.177 oc lower than the pure solvent freezing point temperature. what is the molar mas?

817.66 g/mol

Explanation:

The freezing point change can be calculated by the formula:

Where m is the molality of the solute in NO, Kf is the cryoscopic constant (in K·kg/mol), and i is 1 in this case (because the substance in non-dissociating).

We can calculate Kf of NO with the information given by the problem and the formula:

Where R is the universal gas constant (8.314 J·mol⁻¹·K⁻¹), M is the molar mass of NO (30 g/mol, or 0.03 kg/mol), T f is the freezing point of NO (in K), and ΔH is the heat of fusion.

Now we calculate the molality of the solute in NO:

Molality is equal to the moles of solute per kilogram of solvent:

With the given mass of the solute we can calculate the molar mass:

c is having 4 valence electrons and is bonded to three hydrogens and one sulphur atom, therefore, the number of bond pair is equal to four. as all the valence electrons are used in forming the bonds so, there is no lone pair left on carbon.

s is having 6 valence electrons and is bonded to one other sulfur atom and one carbon atom, therefore, the number of bond pair is equal to 2. as only two valence electrons are used in forming the bonds so, four electrons are left. therefore, two lone pairs are present on s.