lysine,an essential amino acid in human body contain H,C,Oand N.In one experiment,the complete combustion of?

Question

2.175g of lysine gave 3.94CO2 and 1.89g H2O.In a separate experiment 1.873g of lysine gave 0.436g NH3.(a)calculate the emperical formula of lysine.(b)the approximate molar mass of lysine is 150g.What is the molecular formula of the compound?

Answer 1

Something wrong with the figure of CO2, if it is in grams, it is more than the original weight of Lysine.
Trying to see if this can make sense....
Cant continue, the figures provided are incorrect.

1.89g H20 you say,
Grams H20/grams per mole equals moles.
1.89g/(18g/mole) = 0.105 Moles H20
So for each water molecule there was one Oxygen, so
that means there were 0.105 Moles Oxygen. Hmmm.
and it takes two Hydrogen atoms per water molecule, so there were twice as many moles of Hydrogen or 0.210 Moles H

So far we learned that 2.175g Lysine contains 0.210 Moles H.
Hydrogen is 1 g/mole 1amu per mole, so
0.210 Moles H = 0.210g H
So 0.210g H per 2.175g Lysine = 0.09655 x100= 9.655% Hydrogen. Lysine is 9.655% Hydrogen
This will be useful when deturning the molecular formula

1.873g Lysine produced 0.436g NH3.
NH3 is N 14 + H 1+H1 + H1 = 17amu
0.436g NH3/17grams per mole=0.025647 Moles NH3,
and also means that number of moles of N,
and three times as many moles of H.
Moles N * 17 g/mole is 0.43299
converting to percent, is 43.299 percent Nitrogen.
3 moles H per N, so 0.076941moles Hydrogen
H is 1 g/mole so there were 0.076941g H from the 1.873g Lysine yielding 4.1079 percent Hydrogen.

Answer 2

Some are notably low, such as corn protein, which is low in lysine and isoleucine. Certain traditional dishes, such as Mexican corn and beans, Japanese soybeans and rice, and Cajun red beans and rice, combine grains with legumes to provide a meal that is high in all essential amino acids.