00:01
Using the graph, let's answer the following questions for part a.
00:07
On its website, the epa claims that sulfur dioxide levels have fallen by 85 % between 1990 and 2016, so this is claim accurate.
00:16
So if we look at 1990 from our graph, the so2 levels were 124 parts per billion, and in 2016.
00:35
Of our graph, this came down to 18 parts per billion.
00:44
So the reduction in the so2 level would be equal to 104 minus 18 over 124 % and this would be equal to 805%.
01:05
Percent so therefore the epa claim that so2 levels have fallen by 85 percent between 1990 and 2016 is correct and accurate for part b, the epa air quality standard for sulfur dioxide at 75 parts per million.
02:11
In what year did the average us self -red oxide concentration begin to meet this standard? so if we read this off our graph, we can see that as per the graph for the graph for 1990, the united states began to meet the air quality standard of 75 parts per million for sulfur dioxide.
03:28
For c, what is the percent by mass of sulfur in sulfur dioxide? so percent of sulfur, be able to the mass of sulfur, the mass sulfur dioxide times 100 percent.
03:47
32 .1 grams is the mass of sulfur...