**How many kilograms of potassium nitrate will be produced from 50.0 kg of potassium chloride and 50.0 kg of nitric acid in the following reaction?**4KCl + 4HNO _{3}+ O_{2}4KNO _{3}+ 2Cl_{2}+ 2 H_{2}0

Michael Feldman-
Whenever you have the amount of both reactants, you have a
**limiting reactant**problem. For example, if I have 10 slices of bread and 10 slices of swiss cheese, I can make 5 sandwiches at most (I insist that a sandwich must have 2 slices of bread and at least one slice of cheese.) The amount of bread I have limits the amount of product I get.You'll need 4 moles of KCl for every 4 moles of nitric acid, or some of your starting materials will be wasted. The reactant that is present in the smallest molar amount will limit the amount of product you get. So your overall strategy is to find which reactant (the KCl or nitric acid) gives you the lowest yield of potassium nitrate. That's the amount of potassium nitrate you'll actually get.

In a little more detail, the plan is to:

**Find how many kilograms of KNO**You need to convert an amount of one substance (KCl) into an amount of another (KNO_{3}you get from 50 kg of KCl._{3}, so you need a mole-to-mole conversion factor to bridge the two amounts. From the equation, you have 4 mol KCl = 4 mol KNO_{3}. The strategy is50 kg KCl formula wt. KCl mol KCl 4 mol KCl = 4 mol KNO _{3}mol KNO _{3}formula wt. KNO _{3}kg KNO _{3}and the actual setup for this part of the problem is

50 kg KCl ( 1000 g KCl

1 kg KCl) ( 1 mol KCl

74.55 g KCl) ( 4 mol KNO _{3}

4 mol KCl) ( 101.11 g KNO _{3}

1 mol KNO_{3}) ( 1 kg KNO _{3}

1000 g KNO_{3}) **Find how many kilograms of KNO**This calculation is very similar to the one in the previous step._{3}you get from 50 kg of nitric acid.-
**Report the lower of the two predictions as your theoretical yield of KNO**The reactant that limits the amount of product (the "limiting reactant") will be completely consumed in the reaction. There will be some of the other reactant left over after the reaction (which will contaminate the product)._{3}.

General Chemistry Online! How can amount of product (KNO_3_) be predicted from amounts for two reactants (KCl, HNO_3_)?

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Last Revised 08/17/15.URL: http://antoine.frostburg.edu/chem/senese/101/moles/faq/print-limiting-reagent-kcl-kno3.shtml