For each of the three trials of the analysis of the antacid, what was the volume of standardized naoh required to titrate the residual standardized hcl after it reacted with the antacid? enter the volumes in the same sequence as the corresponding mass of antacid sample and to the nearest 0.02 ml, e. g. 37.54 ml.

Iknow the answer is a but i don't know why

The name of the ion, s2-, is: sulfurous ion sulfide ion sulfur ion sulfate ion

Which ocean zone has the most abundant primary producer and why a) the abyssopelagic zone ,du to the absence of light and cold water temperatureb) the bathypelagic zone, due to the absence of light and cold water temperaturec) the mesopelagic zone ,due to uts high light availability and warm water temperature d) the epipelagic zone,due to its high light availability and warm water temperature