Joyce combines 9 atoms of hydrogen and 3 atoms of nitrogen to make 3 molecules of ammonia.Graph this direct variation with nitrogen along the x-axis

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ncchemist eNotes educator| Certified Educator

We are asked to graph the direct variation of the formation of ammonia with nitrogen on the x axis.  That means that hydrogen is represented on the y axis.  Ammonia is NH3, meaning one molecule of ammonia has one nitrogen and three hydrogens.  So this is a N:H ratio of 1:3.  So for x molecules of ammonia formed, we will need x atoms of nitrogen and 3x atoms of hydrogen.  So graphing this as a linear equation requires a slope of 3.  So we can graph the line y=3x to represent the direct variation:

Notice that for each increment along the x axis (nitrogen), we go up the y axis (hydrogen) by three.  So at x=3, we have y=9 which corresponds with the information in the question above.