Potassium chloride (kcl) is sometimes used to treat low blood potassium levels. calculate the concentration of a saturated solution of potassium chloride at 20°c. question continued-? hint: the formula for molarity, a common concentration unit, is m = moles/volume of solution expressed in units of mol/l. you will need to convert from grams of kcl to moles. assume the volume of solution is 100 ml. show your work! info: 36g of kcl is the max 100ml of water could hold at 20°c.

first, consult an activity series chart to determine if al is more reactive than fe. it is, so it will replace the fe. now, one can continue with the problem.

next, make sure you have a correctly balanced equation.

3feo + 2al ==> 3fe + al2o3

now, determine which reactant (feo or al) is in limiting supply.

moles feo present = 125 g x 1 mole/71.8 g = 1.74 moles

moles al present = 25.0 g x 1 mole/26.98 g = 0.927 moles

since from the balanced equation, it take 3 mol feo for every 2 mol al, al will be limiting.

you can determine this simply by dividing moles of each by their coefficient in the balanced equation. for example: 1.74/3 = 0.58 and 0.927/2 = 0.464. al is less, so it is limiting.

finally, using the stoichiometry in the balanced eq. determine mass of fe that can be produced from 0.927 moles of al.

0.927 moles al x 3 moles fe/2 moles al x 55.8 g/mole = 77.6 g