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QUESTION F3

Posted: Wed Oct 02, 2019 4:51 pm
by Daniel Martinez 1k
Question F3 part A asks "(a) Write the formula for nitric acid." Is this a formula that we are already supposed to know? If not, how does one know the formula without actually calculating the empirical/molecular formulas?

Re: QUESTION F3

Posted: Wed Oct 02, 2019 4:59 pm
by Tiffany Vo 3G
I think you're technically supposed to know it because it is basically a nitrate ion (NO3-) with an added hydrogen atom. It tends to come up fairly often in chemistry, so it's really helpful to have it memorized. Assuming that the polyatomic ion that is being protonated ends with -ate (like nitrate), the acid would end in -ic (like nitric acid).

Re: QUESTION F3

Posted: Wed Oct 02, 2019 5:21 pm
by Kylie Lim 4G
I think it's assumed that we have the most common polyatomic ions and their charges memorized

Re: QUESTION F3

Posted: Wed Oct 02, 2019 5:45 pm
by Avnita C_4B
nitric acid falls under the table of memorizing specific ions and their acid/base compounds. Even if you do not perform the calculations for finding empirical formula, nitric acid is derived from the the combination of N and O, for which we have to memorize the ions. Then, you simply add H+ as it is an acid.