Calculate the mole fraction of each component in a solution with 6.87 g of sodium chloride (nacl) dissolved in 65.2 g of water. work must be shown in order to earn credit.

mole fraction of NaCl = 0.03145.

mole fraction of water = 0.9686.

Explanation:

mole fraction of NaCl = (no. of moles of NaCl) / (total no. of moles).

no. of moles of NaCl = mass/molar mass = (6.87 g)/(58.44 g/mol) = 0.1176 mol.

no. of moles of water = mass/molar mass = (65.2 g)/(18.0 g/mol) = 3.622 mol.

∴ mole fraction of NaCl = (no. of moles of NaCl) / (total no. of moles) = (0.1176 mol)/(0.1176 mol + 3.622 mol) = 0.03145.

∵ mole fraction of NaCl + mole fraction of water = 1.0.

∴ mole fraction of water = 1.0 - mole fraction of NaCl = 1.0 - 0.03145 = 0.9686.

answer: the enthalpy of the overall chemical reaction is +87.88 kj or +88 kj.

according to hess's law, the overall enthalpy of a reaction is the difference between the sum of enthalpy values of all the products and the sum of enthalpy values of all the reactants.

δh(reaction) = ∑nδh(products) - ∑nδh(reactants)

δh(reaction) = [δh +δh] - [δh]

δh(reaction) = [1(-287.02) + 1(0) ] - [1(-374.9)] kj = +87.88 kj

here, δh (pcl3) = -287.02 kj, δh(cl2) = 0, δh(pcl5) = -374.9 kj

therefore, enthalpy of the overall reaction is +87.88 kj or +88 kj.