The digestive system of multicellular is made up of several organs that work together to break down food so that it may be used in the body. Unicellular organisms have organelles, similar to organs, which help to digest food that will be used by the cell
Number 13 is D. Mendeleev. He was a Russian chemist and inventor who formulated the periodic table.
In a titration, for an acid to neutralize a base, at the equivalence point, there should be an equal number of moles of H+ and OH-.
Moles of OH- can be found by multiplying the concentration of the base by the volume. (You will need to keep in mind the stoichimetric coefficients if the strong base is Ca(OH)₂, Ba(OH)₂, or Sr(OH)₂.
Moles of OH- = moles of H+
(0.253 M) * 0.005 L = 0.01000 L * c
c = 0.1265 M
The concentration of HBr is 0.127 M.