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if 30ml of .150 M CaCl2 is added to 22.5ml of .1 M AgNO3, what is the mass of the AgCl precipitate?

2 answers

This is a limiting reagent problem. You know that because BOTH reactants are given.
Write the equation and balance it.
CaCl2 + 2AgNO3 ==> 2AgCl + Ca(NO3)2

Convert CaCl2 given to moles. moles = M x L.
Convert AgNO3 given to moles. Again, moles = M x L.

Using the coefficients in the balanced equation, convert moles CaCl2 to moles AgCl.
Same process, convert moles AgNO3 to moles CaCl2.
In limiting reagent problems usually these two values are not the same which means one of them is wrong. The correct value in limiting reagent problems is ALWAYS the smaller value and the reactant producing that value is the limiting reagent.
Now, using the smaller value from above, convert mols AgCl to grams. g = moles x molar mass.
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