Pressure problems equation and barometer?

Question

Nitrogen and hydrogen gases react to form ammonia gas as follows:
N2(g) + 3H2(g) → 2NH3(g)
At a certain temperature and pressure, 4.07 L of N2 reacts with 12.2 L of H2. If all the N2 and H2 are consumed, what volume of NH3, at the same temperature and pressure, will be produced?

Ok so it gives me the liters and grams/moles and its not a limiting reaction. Do I use 273k at 1atm by chance?

And


The compound 1-iododecane is a nonvolatile liquid with a density of 1.20 g/mL. The density of mercury is 13.6 g/mL. What is the height of a barometer column based on 1-iododecane, when the atmospheric pressure is 769 torr?

I have worked several problems silimar to this but the question being in denisty screw me up. Do I some how convert the problem to mm Hg's since 760 mmhg=760 torr = 1 atm to find the height? I am guessing mm hg's.

I really apperciate your time guys. Answers has helped me so much in understanding in class.

For the second one. Do I do 11.33 x 769 = 8,715.33mm? Seems big..really big

Answer 1

For the 2nd problem, if your 11.33 is obtained from 13.6/1.20 = 11.33, your answer is correct.

For the 1st one, realize that the reaction equation informs you that each mole of N2 would react with 3 moles of H2 to form 2 moles of NH3. Check if there is any limiting reactant:
4.07L*3 = 12.2L---indicates that there is no limitaing agent.
Hence NH3 volume is: 4.07L*2 = 8.14L
You do not use 273k or 1atm by any chance, since no one tells you "the same temperature and pressure" would be "273k and 1atm".

Answer 2

dP/dh = c percentand ok are constants P = vital 0 => h of ( dP / dH ) P = ok + a million / 2 (c) * P * P 30 = ok + 0.5 * C * 30 * 30 15 = ok + 0.5 * C * 15 * 15 remedy for C and ok and you're close