English, 11.07.2019 04:50 porfi

Alaboratory analysis of vanillin, the flavoring agent in vanilla, determined the mass percent composition: c, 63.15%; h, 5.30%; o, 31.55%. determine the empirical formula of vanillin.

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C8H8O3 Lookup the atomic weights of the elements involved: Atomic weight carbon = 12.0107 Atomic weight hydrogen = 1.00794 Atomic weight oxygen = 15.999 Now determine the relative moles of each element by dividing the weight percentage by the atomic weight of each element. Carbon = 63.15 / 12.0107 = 5.257811784 Hydrogen = 5.30 / 1.00794 = 5.258249499 Oxygen = 31.55 / 15.999 = 1.97199825 So we have a ratio of carbon : hydrogen : oxygen of 5.257811784 : 5.258249499 : 1.97199825 We want to create a ratio of small integers that comes close. So start by dividing all the numbers by the smallest. Getting: 2.666235523 : 2.666457488 : 1 Not quite there. We could multiply the above values by 1, 2, 3, etc until we get some values close to integers, but the .666 values looks rather close to 2/3, so let's multiply the values by 3 and see what we get. 7.998706568 : 7.999372463 : 3 And this looks good. The ratio looks to be 8:8:3 So the empirical formula is C8H8O3

Answer from: Quest

1. read the following excerpt from franklin d. roosevelt's "fireside chat 19":

on the other side of the picture, we must learn also to know that guerilla warfare against the germans in, let us say serbia or norway, us; that a successful russian offensive against the germans us; and that british successes on land or sea in any part of the world strengthen our hands.

remember always that germany and italy, regardless of any formal declaration of war, consider themselves at war with the united states at this moment just as much as they consider themselves at war with britain or russia. and germany puts all the other republics of the americas into the same category of enemies. the people of our sister republics of this hemisphere can be honored by that fact.

the true goal we seek is far above and beyond the ugly field of battle. when we resort to force, as now we must, we are determined that this force shall be directed toward ultimate good as well as against immediate evil. we americans are not destroyers — we are builders.

analyze the effectiveness of this excerpt. how does it function within the speech as a whole? how does the structure of the excerpt to convey the speech's purpose and key points? support your argument with evidence from the speech. (10 points)