Molarity = number of moles/number of litres

Moles= molarity * number of litres <- this is what we use for finding the limiting reagent!

Litres = number of moles/molarity

Litres just means grams when we are using it in our case for limiting reagents

 Mole: measure of amount of chemical substance

Molar is the unit -> M

 

Unit for molarity = molar

            Here are some examples of how you would do a type of problem like this:

            1.    What is the molarity of a solution of potassium chloride which contains 1.35 moles of solute in a total volume of 0.716L?

 

-                       1.35/0.716 = 1.89L

 

 

            2.    How many moles are in 352mL of a 1.73M solution of NH4NO3?

 

-                   Volume = 0.352L

-                       Number of moles = molarity * number of litres

-                       0.352 * 1.73 = 0.61 mol

 

            3.    What volume in mL of a 0.241M solution of sodium chloride would be required if you wanted 0.200moles of solute?

 

-                           Number of litres = number of moles/ molarity

-                   0.200/0.241= 0.831

-                   0.831 * 1000 = 831 mL

 

            4.    How many moles are in 0.408L of a 0.685M solution of sodium iodide?

 

-                       number of moles = molarity * number of litres

-                       0.685 * 0.408 = 0.28 mol

 

                5.    What volume in L of a 0.688M solution of lithium iodide would be required if you wanted 0.142moles of solute?

-                           Number of litres = number of moles/ molarity

-                       0.142/ 0.688 = 0.206 L

 

 

 

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