We use the relationship:
"Molarity"="Moles of solute"/"Volume of solution"Molarity=Moles of soluteVolume of solution, and thus to get the number of "moles"moles we multiply the "volume"volume by the "molarity"molarity to get an answer in "moles".moles.
And for your problem, there are:
5xx10^2*mLxx10^-3*mL*L^-1xx2.0*mol*L^-1=1*mol5×102⋅mL×10−3⋅mL⋅L−1×2.0⋅mol⋅L−1=1⋅mol with respect to KNO_3KNO3.
Note the use of the units in the calculation. We wanted an answer in molmol; the calculation gave us an answer in "mol"mol. Chemists (and physical scientists) often include units in their calculations to ensure that they perform the right order of operations: "do I divide or do I multiply?"do I divide or do I multiply? Anybody can make a mistake, and everybody has.
And since "moles"="mass of solute"/"molar mass of solute"moles=mass of solutemolar mass of solute, there are 1*cancel(mol)xx101.10*g*cancel(mol^-1)=101.1*g
