6. allicin is the compound responsible for the characteristic smell of garlic. an analysis of the compound gives the following percent composition by mass: c: 44.4 percent; h: 6.21 percent; s: 39.5 percent; of: 9.86 percent. calculate its empirical formula. what is its molecular formula given that its molar mass is about 486g

Answer : The empirical formula of a compound is,  and the molecular of the compound is,

Solution : Given,

If percentage are given then we are taking total mass is 100 grams.

So, the mass of each element is equal to the percentage given.

Mass of C = 44.4 g

Mass of H = 6.21 g

Mass of S = 39.5 g

Mass of O = 9.86 g

Molar mass of C = 12 g/mole

Molar mass of H = 1 g/mole

Molar mass of S = 32 g/mole

Molar mass of O = 16 g/mole

Step 1 : convert given masses into moles.

Moles of C =

Moles of H =

Moles of S =

Moles of O =

Step 2 : For the mole ratio, divide each value of moles by the smallest number of moles calculated.

For C =

For H =

For S =

For O =

The ratio of C : H : S : O = 6 : 10 : 2 : 1

The mole ratio of the element is represented by subscripts in empirical formula.

The Empirical formula =

The empirical formula weight = 6(12) + 10(1) + 2(32) + 1(16) = 162 gram/eq

Now we have to calculate the molecular formula of the compound.

Formula used :

Molecular formula =

Therefore, the molecular of the compound is,

the potential energy of the reactants is 200j.

from the energy diagram, the energy of the product formed is 350j; this means that, this reaction is an endothermic reaction, because it absorbs energy from its environment.