A 0.4000 g sample that contained 96.4% Na2SO4 (142.04 g/mol) required 41.25 mL of barium chloride solution to reach the endpoint in a precipitation titration. What is the molarity of the BaCl2 solution?

0.0658 M

Explanation:

The reaction that takes place is:

Na₂SO₄(aq) + BaCl₂(aq) ↔ BaSO₄(s) + 2NaCl(aq)

First we calculate the number of Na₂SO₄ moles:

Now we convert to moles of BaCl₂:

Finally we divide by the volume to calculate the molarity:

i think a, hope it .

explanation:

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.