Where is the reaction used in real life?

What are three improper fractions for four and 1 half? Which are divisible by 9? What is the equation of the ellipse with foci (0 6) (0 -6) and co-vertices (2 0) (-2 0)? What is 48.001 rounded to the nearest hundredth? The sum of two numbers is 19 and their product is 78. What is the smaller number? How much will it take to fill up a 25 gallon tank? What is 7.4383 to the nearest tenths place? What does 223 ½ - 111 ⅔ equal? How and why variation occur in rate and sequence of development and learning? A man walks 30 meters forward then turns around and walks backward 10 meters what is the displacement of the man? What fractions are equivalent to 81.8 percent? What is 1 and five sixths in a decimal? How many equal angles does a nonagon have? Is 65 a multiple of 3? How do you gain 4 inches in vertical within 4 weeks? Diameter of a grain of sand in scientific notation? Does a hexagon have four right angles? What is the relationship between rolled distance and time taken? What are the 2 numbers that tel you the exact location on the graph called? What would make something full or complete where there is something lacking?

Where is the reaction used in real life?