A standard solution is prepared by dissolving 5.30 g of sodium carbonate, Na2CO3, in 250 cm³ of distilled water in a volumetric flask. A 10.0 cm³ sample of this solution is removed by bulb pipette and diluted with water to the final volume of 0.100 dm³. Calculate the concentration, in mol dm-3, of the diluted solution.

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.

your answer would be “dry”

c. orbital shape i hope this is correct