Consider a gaseous binary compound with a molar mass of 62.09 g/mol. When 1.54 g of this compound is completely burned in excess oxygen, 1.34 g of water is formed. Determine the formula of the compound.
-
A binary compound has only two elements. Hydrogen is a given by the product H2O
XxHY+O2-->H2O+extraneous product
Water has a molar mass of 18.016g/mol.
1.34 g H2O (2.0158 g H2/18.0148 g H2O) = 0.149 g H
(0.149 g H/1.54g unkown) x 100= 9.68% hydrogen 90.32% unknown
9.68%Hydrogen(62.09g/mol)/1.008g/molH= 6.00mol Hydrogen
XxH6 is the new equation
6molH(1.008g/mol)=6.048g
62.09-6.048=56.042g unknown
This is where things become a little murky.
We do not know the identity of the unknown! Is it iron, nitrogen, carbon etc?
62.09g/mol = FeH6
56/2 = 28: Si: Si2H6
56/3 does not apply to any elements
56/4 = 14 N4H6
So you have three options: FeH6, Si2H6, and N4H6.
We can determine the moles of water to moles of unknown:
1.34gH2O/18.016g/mol=.0743mol water
1.54gunknown/62.09g/mol=.0248mol unknown
***this is a ratio of 3mol water: 1 mol unknown***
Create equations for the possible reactants:
2 Si2H6 + 7 O2 = 4 SiO2 + 6 H2O --> a 3 water to 1 unknown ratio!!
The other two options don't create any possible outcomes to form a 3 water: 1 unknown ratio.
My answer: Si2H6
XxHY+O2-->H2O+extraneous product
Water has a molar mass of 18.016g/mol.
1.34 g H2O (2.0158 g H2/18.0148 g H2O) = 0.149 g H
(0.149 g H/1.54g unkown) x 100= 9.68% hydrogen 90.32% unknown
9.68%Hydrogen(62.09g/mol)/1.008g/molH= 6.00mol Hydrogen
XxH6 is the new equation
6molH(1.008g/mol)=6.048g
62.09-6.048=56.042g unknown
This is where things become a little murky.
We do not know the identity of the unknown! Is it iron, nitrogen, carbon etc?
62.09g/mol = FeH6
56/2 = 28: Si: Si2H6
56/3 does not apply to any elements
56/4 = 14 N4H6
So you have three options: FeH6, Si2H6, and N4H6.
We can determine the moles of water to moles of unknown:
1.34gH2O/18.016g/mol=.0743mol water
1.54gunknown/62.09g/mol=.0248mol unknown
***this is a ratio of 3mol water: 1 mol unknown***
Create equations for the possible reactants:
2 Si2H6 + 7 O2 = 4 SiO2 + 6 H2O --> a 3 water to 1 unknown ratio!!
The other two options don't create any possible outcomes to form a 3 water: 1 unknown ratio.
My answer: Si2H6
-
Btw the answer was N4H6.
Report Abuse
-
If the answer is N4H6 , then why do you give BA to an incorrect answer. This closes the question to other contributors . You still do not know how to get the correct answer. I would like to show you how, but the question is closed. Always better to wait for correct answer
Report Abuse
-
People say what the answer is, but nobody can seem to explain why it is actually N4H6, nor can they rule out why it cannot be Si2H6. You can validly argue either of these answers, as there is not enough information to let one know what the other atom is along with the hydrogen.
Report Abuse
-
Si2H6 (disilane) is a gaseous binary compound and follows all mol and mass ratios given. If someone can explain to me why this isn't a valid answer, it would really help me out, as I can't find any reason to why it would be incorrect.
Report Abuse