How do you do this problem?
In the reaction
CaCl2(aq) + Na2SO4(aq) → CaSO4(s) + 2 NaCl(aq)
422 mL of 0.188 M aqueous Cl- reacts stoichiometrically according to the balanced equation. Calculate the amount of moles of SO42- are required to proceed the reaction.
Comments
Hi Ush!
First off, the reactants are aqueous so then they are assumed to be dissolved. Thus, we can pretty much assume that SO42- is the same stoichiometrically as Na2SO4, ratio wise. So first find the amount of moles of Cl- that is reacting. 0.188M = (x moles)/(0.422L) where x represents the unknown amount of Cl- moles. Solve for x and it should be about 0.0793 moles of Cl-.
Now we can stoichiometrically relate the amount of Cl- reacting to the amount of SO42- needed. Based on the equation, 1 mol of SO42- reacts with 2 moles of Cl- and so simply divide the moles of Cl- by two and you should get the amount of moles of SO42- required to react which is about 0.0397 moles of SO42-.
These were all done in significant figures!
I hope this helped and good luck on chemistry