The answer will be D because the reaction is what's first(A) and then it is the product that comes out.
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:

B because A is the experiment so you won't have the data until after, not C because that's when you have your final verdict on the experiment not just looking at results, and not D because a hypothesis is something you form before an experiment. Hope this helped!<span />
Answer:
As there are many units of mass and volume covering many different magnitudes there are a large number of units for mass density in use. The SI unit of kilogram per cubic metre (kg/m3) and the cgs unit of gram per cubic centimetre (g/cm3) are probably the most commonly used units for density.
Explanation: