Answer:
a
Explanation:
because titration by definition, is used to determine the concentration of one reactant in an aqueous solution, it requires a burette to accurately measure the volume of a solution and endpoints in acid-base titration can be determined by a colour indicator or a pH meter
white phosphorus is used in flares and explosives, so may be important in warfare, etc. Red phosphorus is used in matches (side of matches) and in fertilizers which are essential to growing plants. I don't know if that is economically important, but there are many ways that phosphorus benifit the economy. One downside on the economy is that phosphorus is one of the main ingredients in meth, which of course causes trouble for the economy ( law enforcement, medical, etc. )
Answer:
because it is two substances reacting together to create a new substance
Explanation:
when iron rusts, iron molecules react with the oxygen molecules creating iron oxide aka rust.