The following data were obtained from experiments to find the molecular formula of lidocaine, a local anesthetic, which contains only carbon, hydrogen, nitrogen, and oxygen. complete combustion of a 3.54-g sample of lidocaine with excess o2 formed 9.32 g co2 and 3.00 g h2o. another sample of mass 2.35 g was found to contain 0.281 g of n. the molar mass of lidocaine was found to be 234. find the molar formula of lidocaine.

C₁₄H₂₂N₂O    

Explanation:

Let's call the molecular formula CxHyNzOw. For the combustion reaction, all the carbon will form CO₂ and all the hydrogen will form H₂O

CxHyNzOw + O₂ → CO₂ + H₂O

So, the molar mass of H is 1 g/mol, of C is 12 g/mol, of O is 16 g/mol, and of N is 14 g/mol. The molar masses of the compounds are

CO₂ = 12 + 2x16 = 44 g/mol

H₂O = 2x1 + 16 = 18 g/mol

The number of moles is the mass divided by the molar mass, so:

CO₂ = 9.32/44 = 0.2118 mol

H₂O = 3/18 = 0.1667 mol

In 1 mol of CO₂, there is 1 mol of C, so the number of moles of C is 0.2118 mol, and in 1 mol of H₂O there is 2 mol of H, so the number of moles of H is 2x0.1667 = 0.3334 mol, which is the number of moles in the lidocaine. The masses are:

C = 0.2118x12 = 2.5416 g

H = 0.3334x1 = 0.3334 g

So, the percentagens of the compounds are:

C = 2.5416/3.54 = 0.718 = 71.8%

H = 0.3334/3.54 = 0.094 = 9.4%

For N, based on the other experiment:

N = 0.281/2.35 = 0.1196 = 11.96%

So, the percentage of oxygen must be 100 - (71.8 + 9.4 + 11.96) = 6.84%

In 1 mol of lidocaine, there is 234 g, so the masses and the number of moles of the compounds are:

C: m = 0.718x234 = 168 g

n = 168/12 = 14 mol

H: m = 0.094x234 = 22 g

n = 22/1 = 22 mol

N: m = 0.1196x234 = 28 g

n = 28/14 = 2 mol

O: m = 0.0684x234 = 16g

n = 16/16 = 1 mol

So, the molecular formula is C₁₄H₂₂N₂O.

hurricanes form when warm, moist air from the ocean surface quickly rises into the atmosphere and forms storm clouds and rain. when the clouds are formed, heat is released which warms the cool air in the upper regions of the atmosphere so that the cycle can continue. which two phases of the water cycle are repeated in this process?