Question

A compound is composed of 58.8% c, 9.8% h, and 31.4% o, and the molar mass is 102 g/mol. what is the molecular formula for this compound?

Answer 1

Answer:Thus the molecular formula is C5H10O2

Explanation: 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 = 58.8 g

Mass of H = 9.8 g

Mass of O = 31.4 g

Step 1 : convert given masses into moles.

Moles of C =

Moles of H =

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 O =

The ratio of C : H : O= 2.5 : 5 : 1

Converting them into whole number ratios:

Hence the empirical formula is

The empirical weight of = 5(12) + 10(1) + 2(16)= 102g.

Given :The molecular weight = 102 g/mole

Now we have to calculate the molecular formula.