10 POINTS BEST ANSWER!

Question

can someone answer number 75 for me pleaseeee? i have my aug 08 regents on wednesday and i wanna know how to do this!

http://www.jmap.org/JMAP/IJMAP/Chemistry/RegentsExams/0606ExamCH.pdf

#75 AND THANKSSSSSS

Answer 1

19:not too sure

27:dunno answer

43:not too sure

45:not too sure

52:dunno answer

65:dunno answer

75:seawater

Answer 2

Seawater.  Remember, pH is base-ten logarithmic, so something with a pH of 2 lower than something else is 10^2 = 100 times more acidic.  For the record, stomach acid is hydrochloric acid... bile is produced by the liver to aid in the digestion of lipids.

Edit: Dang, somebody beat me to it.  I wish this had been around when I was in school, people competing to answer my questions...

Answer 3

75. sea water... just know stomach juice is acid aka bile. So, the lower the product the more acidic. You want to go 100 times lower, so do some math and you will the correct answer.

I tried to figure out the other ones, but I don't study this, I just tried it from learnig it breifly.

#45 might be 3?

Look all of the unknown questions up on the internet or call someone.

Answer 4

The answer is seawater, since the pH scale is logarithmic, a change of 1 makes a 10 fold difference, so a change of 2 represents a 10^2 difference.

The answer to 19, the endothermic reaction, is:

N2(g) + O2(g) → 2NO(g)

From Wikipedia, "Because the heat of formation of NO is endothermic, its synthesis from molecular nitrogen and oxygen requires elevated temperatures, >1000°C. A major natural source is lightning.":

http://en.wikipedia.org/wiki/Nitric_oxid...

For 27, I don't have access to the reference table, but the answer is number 4, C-14 and N-16.

For 43, the compound has 4 carbon atoms in a chain, which means that it's but- at the beginning, and it has a double bonded oxygen atom at the end of the chain which makes it an aldehyde. Therefore it is called Butanal.

The answer to 45 is Amide:

http://en.wikipedia.org/wiki/Amide

For 52 I'd need to see Reference Table J. However, Iron is more reactive than Hydrogen, and so it "steals" the Nitrate ion away.

For 65, the reaction and energy given is all for 1 mole of ethanol, it asks you for the heat energy produced when 2 moles of ethanol are reacted, therefore the answer is 2 * 1367 = 2730 KJ to two significant figures.