How do you calculate the mass of lead (II) nitrate, #Pb(NO_3)_2#, necessary to make 50.0 mL of a 0.100 M solution?

1 Answer
Apr 27, 2017

Answer:

1.655 gm

Explanation:

First, we'll look at formula for Molarity.

Molarity = No. of moles of solute / Vol. of solution (in L)

Before putting values, it helps to know that #50 mL = 0.05 L#

Now, #0.1M = n/(0.05L)# where #n# are the no. of moles of #Pb(NO_3)_2#

#n = 0.005# moles

Now we also know that #n =# given mass / molar mass

Molar mass of #Pb(NO_3)_2 = 207 + 2(14 + 3(16)) = 331 (gm)/(mol)#

Given mass #= 331 (gm)/(mol) xx 0.005 mol#

So mass of #Pb(NO_3)_2 = 1.655 gm#