How to Determine the Final Concentration of a Mixture – Part 1

Stoichiometry is the relationship between the quantities of reactants and products before, during, and after chemical reactions.


A chemical equation is the representation of a chemical reaction in the form of symbols and chemical formulas. The coefficients next to the symbols and formulas of entities are the absolute values of the stoichiometric numbers.

The limiting reagent (aka limiting reactant/agent) in a chemical reaction is a reactant totally consumed when the chemical reaction is completed.

Checking the limiting reactant (LR): To take the number of moles of each reactant and divide it by its stoichiometric coefficient in the balanced equation. The quotient with a lower value indicates the LR.

When two or more solutions are mixed, one must add the volumes of all solutions.

Question:

What is the final concentration of Pb2+ ions when a 100 mL 0.20 M Pb(NO3)2 solution is mixed with a 100 mL 0.30 M NaCl solution?

Solution:



Click/tap to enlarge the image

Strenuous stoichiometry❓ Let Chemaficionado know in the comments below or at mychemistryhomework@gmail.com❗

References:

(1)    Limiting reagent. Wikipedia. https://en.wikipedia.org/wiki/Limiting_reagent.

‌(2)    Brown, C.; Ford, M. Higher Level Chemistry, 2nd ed.; Pearson Education: Harlow, Essex, 2014.

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