Periodic table!
The periodic table organizes elements by their chemical properties (mainly through vertical columns known as groups) and increasing atomic number.
15 ppm
1.5 × 10-2 ppm
1.5 × 104 ppm
3.1 ppm
1.5 × 10-2 ppm
Answer:
0.005404 M
Explanation:

Since you added an excess of sodium carbonate you warrantied that all the
in the sample reacted with it. So we can say that the insoluble lead (II) carbonate
contains all the
ions in the original sample.
The moles of
are:

One mol of
is required to form one mol of
. So, the stoichiometric relationship between them is 1:1.
Knowing this, 0.00054 is also the number of moles of
in the original sample.
So, the concentration of
in the original sample is:
