Posted by Chemistry Chick on .
Calculate the molarity of a solution if 300.0 mL of it contains 16.8 g of KNO3.
[Use formula weight: KNO3, 101.11 amu]....Question do I need to convert 300.0 mL to L? My initial set up looks like this: (16.8g/101.11amu)/300.0 mL my answer turns out to be 0.000553852....however the correct answer is 0.533M...thanks a billion!
Okay I think i figured it out...the answer given for this problem: 0.533M is incorrect! The right answer is: 0.553M b/c u do have to convert 300 mL into L. so problem looks like this: (16.8g/101.11)/0.3L
Your second post is correct. The definition of molarity is M = moles/L. That's why the 300 mL must be converted to 0.300 L.