An excess of sodium carbonate, Na, CO3, in solution is added to a solution containing 17.87 g CaCl2. After performing the experiment, 13.19 g of calcium carbonate, CaCO3, is produced. Calculate the percent yield of this reaction.

Approximately .

Explanation:

Balanced equation for this reaction:

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Look up the relative atomic mass of elements in the limiting reactant, , as well as those in the product of interest, :

Calculate the formula mass for both the limiting reactant and the product of interest:

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Calculate the quantity of the limiting reactant () available to this reaction:

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Refer to the balanced equation for this reaction. The coefficients of the limiting reactant () and the product () are both . Thus:

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In other words, for every of formula units that are consumed, of formula units would (in theory) be produced. Thus, calculate the theoretical yield of in this experiment:

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Calculate the theoretical yield of this experiment in terms of the mass of expected to be produced:

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Given that the actual yield in this question (in terms of the mass of ) is , calculate the percentage yield of this experiment:

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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.