Cyclohexene, a hydrocarbon, has a molar mass of 82.1 g/mole. if the combustion of 0.8300 g cyclohexene produces 0.9102 g h2o and 2.668 g co2, what is the molecular formula of this compound?

Answer is:  the molecular formula is C₆H₁₀.

Chemical reaction: C₆Hₓ + yO₂ → 6CO₂ + x/2H₂O.

m(H₂O) = 0.9102; mass of the water.

n(H₂O) = m(H₂O) ÷ m(H₂O)  

n(H₂O) = 0,9102 g ÷ 18 g/mol

n(H₂O) = 0,0505 mol.

From chemical reaction: n(H) = 2 · n(H₂O).

n(H) = 0.101 mol.

m(CO₂) = 2.668 g; mass of carbon dioxide.

n(CO₂) = 2.668 g ÷ 44 g/mol.

n(CO₂) = 0.0606 mol; amount of the substance.

n(CO₂) = n(C) = 0.0606 mol.

n(C) : n(H) = 0.606 mol : 0.101 mol.

n(C) : n(H) = 6 : 10; proportion of carbon and hydrogen atoms in cyclohexene.

Explanation;

Given Data:

Solution:

% of C = (mass of CO2/mass of compound)× (12/44)×100

% of C = (2.66÷0.8300)×(12/44)× 100 = 87.40 %

% of H = (mass of H2O/mass of compound)× (2/18)×100

% of H =  (0.910÷0.8300)× (2/18)×100 = 12.18 %

Niiw we calculate moles of C and H from % as follow

moles of C = 87.40/12 = 7.2 mol

moles of H = 12.18/1 = 12.18 mol

In we take atomic ratio

                 C     :     H

         12.18/7.2 :   7.2/7.2

           1.69       :     1

multiply atomic ratio by 3 to get whole no.

  C : H = 3 (1.69:1) = 5 : 3

So empirical formula is C3H5.

Calculations of molecular formula:

empirical formula mass of C3H5 = 41

  n = molar mass of compound /empirical formula mass

 n = 82.1/41   = 2

Molecular mass =  n × empirical formula = 2 × C3H5 = C6H10

b is the correct

for step 7 table c on the lab "newtons law of action"   the average time it took the car to travel .25 meters   was 1.92 seconds.

the average time it took the car to travel 0.50 meters was 2.61 seconds

hope this : )